Antarctic ozone today:  The 2025 ozone hole filled in at the end of November. The 2025 ozone hole grew to around 20 million square kilometres (msqkm) in late August, the largest for that time over the last decade and peaked at 23 msqkm on September 9. It slowly shrunk to around 12 msqkm in late October, comparable to the last couple of years. It then shrank more rapidly and was gone by the end of November, the earliest for over a decade. The  polar vortex peaked at around 32 msqkm in early September, about average. It slowly shrank during October, then more rapidly in November and had gone by mid December. The area with potential PSCs began to grow from early May and reached its maximum extent of 28 msqkm in late July. It had declined to zero by mid October, slightly earlier than the mean. Temperatures throughout the Antarctic stratosphere are above the PSC formation temperature, though are cooling. The temperature of the ozone layer is warmest just outside the forming polar vortex and declines a little towards the pole and more towards the equator. Ozone values are still relatively uniform across the continent, though are building outside the forming polar vortex. They currently range from a low of around 240 Dobson Units (DU)  to a high of around 360 DU.  The ozone hole clipped the tip of South America on September 17 and was over South Georgia from September 19 to 20, October 5 to 7 and October 11.

Our thoughts and prayers remain with our Ukrainian colleagues in Kyiv and at Vernadsky, who continue with their scientific work despite the invasion of their country.

September 16 is World Ozone Day.

See the final situation report for last year for information on the 2024 - 2025 season.

Notes:  An ozone hole is defined as an area with values below 220 Dobson Units (DU).  On average a column of air will hold 300 DU of ozone, equivalent to 3mm of ozone at sea-level pressure.  Most of the ozone is between 10 and 40 km with a peak at around 20 km.   The Antarctic ozone hole is usually largest in early September and deepest in late September to early October.  Prior to the formation of ozone holes, Antarctic ozone values were normally at their lowest in the autumn (ie March).  On occasion atmospheric vertical motions create small areas with ozone substantially below the long term average.  Different satellites give different views of the exact ozone distribution.  The continent covers 14 million sq. km.  There are marked differences between the various satellite ozone measurements and analyses.  The KNMI analysis and TEMIS forecasts are close to the observed values, whereas the Canadian analysis seems largely based on SMOBA data and is clearly at variance with ground based observations.  

UNEP assessements: September 16 is world ozone day, and in 2009 the final UN Member State to ratify the Montreal Protocol signed up.  All 197 Member States have now ratified the protocol up to and including the Beijing amendments.  2007 was the International Year of the Ozone Layer.  A summary of the WMO/UN 2014 Ozone Assessment, the  Assessment for Decision-Makers was released on 2014 September 10.  2017 was the 30th Anniversary of the Montreal Protocol.  UNEP released the 2022 Scientific Assessment of Ozone Layer Depletion in 2023 January.  An emerging threat to the ozone layer is through aluminium pollution caused by the re-entry of satellites; these effects were not assessed in the 2022 report.

News:  Observations reported in Nature in May 2018 showed that the rate of decline of CFC-11, an ozone depleting substances in the atmosphere, which is also a greenhouse gas, had become slower than predicted.  This suggested that either something unusual was taking place in the atmosphere or that there were additional man-made emissions.  The paper suggested that the most likely reason was illegal manufacture and release from somewhere in eastern Asia.  Investigation by the EIA found that production of polyurethene foam in China could explain the observed changes.  They encouraged the Chinese government to take immediate action.  This became news again in May 2019 when another paper was published in Nature.  The Chinese government took action and by 2021 the rate of decline had returned to that expected.

Observations from Halley since 1994 (the year when ozone depleting gasses were at their peak according to one estimate) show a slow increase of about 1 DU per year in the minimum ozone amount recorded each October. However, the inter-annual variation is such that this trend is not quite significant at the 99% level, ie the data is also just consistent with no change in the minimum amount.  Although the amount of ozone destroying substances in the atmosphere is going down, the inter-annual variation in the size and depth of the ozone hole is largely controlled by the meteorological conditions in the stratosphere.  The provisional Halley 2015 October minimum value was lower than that of 2014, 2013 and 2012 and this was due to the prevailing meteorological conditions.  It was also influenced by the eruption from Calbuco in southern Chile.  Models suggest that recovery may be more rapid after 2010.  The 2019 October ozone minimum at Halley was the highest since the split ozone hole of 2002 and the overall springtime minimum the highest since 1982.  The springtime (ie September and October) minimum ozone values at Halley are slightly better fitted by a quadratic than a linear fit.  It is still too soon to say that we have had the worst ever ozone hole, particularly as there has been no major volcanic eruption in the Southern Hemisphere since 1992.  There has also been little cooling of the lower stratosphere since the mid 1990s.  A simple linear extrapolation of the trend in minimum values gives the final year with ozone hole levels as 2070, whilst the quadratic fit suggests 2035, though the error bars on this estimate are very large.   Satellite data, which shows good agreement with the Dobson data, has been used to fill the gaps since 2016. [graphs updated 2026 March 11]

Click on a thumbnail to get the latest graph or high resolution images, which are updated more frequently than the thumbnails.  

Halley - Total ozone:  The Dobson ozone observing season at Halley normally begins at the end of August and ends in mid April.  Very early and late season observations are made with the Sun at low elevation, and are less accurate than those made during the main observing period of September 6 to April 6.  See the final situation report for 2019 for further information. Today there are no staff on the station during the Antarctic winter and all observations are made by automated instruments, which only observe the zenith sky. The station was re-occupied for the 2025/26 season in late November and closed in early February. The automated Dobson suffered technical issues in 2024/5 and was returned to Europe for maintainance. It has now been calibrated and has returned to Halley. The SAOZ instrument functioned well until March 2025, then stopped producing data, but this was restored when the station was re-occupied in November. In 2026 it stopped in February, but then restarted in March. Manual Dobson observations were made from November until staff left the station at the end of January 2026. The autoDobson stopped on March 20 due to an as yet undiagnosed mechanical failure.

Early SAOZ observations from November 16 were just above the ozone hole threshold. They rose from late November to reach a peak of 345 DU in mid December and then fell to the autumn minimum at around 280 DU in mid March. Values have since remained around 290 DU. Manual observations started on November 23 and were similar, though the calibration constants need a small adjustment. The autoDobson started on November 30 and needs some adjustment to the zenith equation constants. All three however were in good agreement.

Rothera - Total ozone:    Real-time graphs showing current ozone and NO2 levels.   Mean ozone values were around 270 DU at the June solstice and slowly fell to around 170 DU in late October, with variation due to strong wave activity with a period of about 20 days. Mean ozone values dropped to 235 DU in late June, mostly due to dynamic forcing. Ozone values remained near their minimum until late October then rose dramatically to a daily peak of 377 DU on October 31. They fell back again to 215 DU in early November as the residual ozone hole returned over the station, but then rose to a peak of around 320 DU in mid December, a little above average. During 2026 they have remained fairly close to average, falling to the autumn minimum of around 280 DU in late February then rising to around 300 DU by late April. They have now fallen to around 280 DU.  Overall the pattern for the season has been close to average. The lowest value seen this season was 137 DU on August 3 and the highest was 377 on October 31. The station was within the ozone hole from July 30 to August 22, from September 1 to October 26 and from November 6 to 13.

Vernadsky - Total ozone:   Vernadsky station is run by the National Antarctic Scientific Centre of Ukraine.  It is some 250 km north of Rothera.  The observing season began in late July when values were around 290 DU. By early August they were around 240 DU and had broadly fallen to around 210 DU by mid October, but with variation due to wave activity. There was a brief rise in late August, with daily values reaching 399 DU as the ozone hole swung away from the station. They rose rapidly to 315 DU at the end of October, then fell to 230 DU in early November. They rose rather irregularly to a peak of around 330 DU in late December. Values broadly fell during early 2026 to an autumn minimum of  around 290 DU in early March. They had risen to around 320 DU by the end of April. The lowest value seen this season was 169 DU on October 5 and the highest 399 DU on August 27 and November 1.

Superimposed on the general trends during the year are fluctuations with periods of days to around a month and values can change by over 50% in a few days in the spring when the polar vortex rotates across the station, which is usually near the edge region of the polar vortex.   Very early and late season observations are made with the Sun at low elevation, and are less accurate than those made during the main observing period of August 6 to May 6.  The instrument constants were revised on 2023 November 14 and previously published values for 2023 have changed by a small amount. A further small revision is likely in late 2024.

Temperature and PSCs:   The 100 hPa pressure level is near the base of the ozone layer, but is reached by most radiosonde flights.    The temperature at this height is sufficiently cold from July to October that polar stratospheric clouds (PSCs) can form.   Note: "the normal" is used to refer to the long term mean for the time of year.

Both Halley and Rothera see displays of nacreous clouds.  Those at Halley are of the form described during the IGY as "ultra-cirrus".   Clouds were seen at Rothera during the 2025 season.

Halley - 100 hPa temperature:   Radiosonde flights are only made during the short summer season. The temperature was around  -63°C when flights started for the 2025/26 season on November 24 and rose smoothly to a peak of -39°C in mid December. They then fell to a trough of -43°C at the New Year before rising back to -42°C. Flights stopped at the end of January when the station closed for the winter.

Peninsula - 100 hPa temperature:   The "Peninsula temperature" is usually the mean of five flights per week from Rothera and one from Marambio and may include other stations when available.  Since the end of May the 100 hPa temperature was generally cooler than average and reached a minimum of around -80°C in mid August. There was a slow rise to around -75°C in mid October and thereafter a rapid rise, which reached -58°C at the end of October, before falling back to -68°C in early November. It continued to rise steadily, but paused for a fortnight at around -54°C before rising again to a peak of  -42°C in mid December. The temperature has broadly been close to average in 2026. The lower stratosphere is now cooling and the 100 hPa temperature had reached  -63°C by mid May. There is strong wave activity with a period of about 20 days. There is often large day to day variation during the spring because the area is in the edge region of the circumpolar vortex.  

All the colder winters in the ozone layer have been within the last 15 years. 

Arctic:  Temperatures are above the Polar Stratospheric Cloud (PSC) formation temperature. Ozone values are high outside the former polar vortex and range from around 310 DU to around 470 DU. The polar vortex began to form much later than usual and was much smaller than usual for much of the season. It recovered to near normal at the end of February with a peak of 12 msqkm. It then declined as usual and was gone by early April. The area with PSC came and went during January, reaching at most 3 msqkm, but was near zero throughout February. Ozone amounts over the UK are currently around 380 DU, but are variable.

The north polar vortex is usually smaller and more disturbed than the corresponding one that forms during the Antarctic winter.  

There are sometimes significant differences (over 100 DU) between modeled, satellite and ground-based measurements, particularly when there is large variation in total column ozone.  Ozone values over the Arctic during 2022/23 are shown in our Northern Hemisphere OMI movie.   For more UK information see the DEFRA UK Stratospheric Ozone Measurements page.    

Equator: Ozone levels are normally lowest over the tropics and TEMIS plots show nothing unusual.  The latest theories on how the ozone layer will change in response to increased carbon dioxide in the atmosphere suggest that there will be a slow decline in ozone amounts over tropical and sub-tropical regions. These areas may also be affected by the consequences from the increasing number of satellite launches and re-entries distributing aluminium oxide particles in the upper atmosphere.

Satellite: Satellite imagery gives a global perspective on the ozone hole, though there are marked differences between the different satellites, demonstrating the need for verification by ground based stations. Our 2022/2023 Antarctic ozone hole movie was produced from OMI images, which are generally well calibrated with respect to ground based measurements. KNMI analyses are shown on the Canadian Met Service world ozone maps pages. The KNMI model is generally better at analysis and forecasting in the Antarctic. The Canadian composite plot appears to give undue weight to the SMOBA observations. The SMOBA and TOAST analyses both use SBUV and TOVS data, but the TOAST algorithm may at times over-estimate ozone depletion. In 2022/23 the SMOBA analysis did not pick up ozone depletion over Antarctica and gave unreasonably high values over the Arctic. It was possibly being affected by smoke from forest fires. US NWS CPC plots from NOAA show the current area of the ozone hole, though note that this is often a preliminary plot. The Sciamachy uv index from the ESA  Tropospheric Emission Monitoring Internet Service shows the exposure risk at any location.  TEMIS also provide forecasts of total ozone out to 9 days.

Measurements reported here refer to ozone in the "ozone layer", where most of the ozone in the atmosphere is found.  This "layer" stretches from roughly 10 to 40 km above the Earth's surface, with a peak at around 20 km.  Bringing all the ozone in the "layer" down to ground level would give a thickness of around 3mm of pure ozone, which reduces to around 1mm at the height of the ozone hole.  A little ozone also exists closer to the Earth's surface and research shows that natural halogens in Antarctica can produce depletion in this near surface layer.  The theoretical basis for the formation of the Antarctic ozone hole and its link with the halogen chemistry of man-made substances is well established and the mechanism is described at sites such as the Ozone Hole Tour at the Cambridge University Centre for Atmospheric Science.  

---

Background and related material

Hannah Fry explained about fridges in a programme broadcast on BBC2 on 2025 April 9

"Rare Earth" on BBC Radio 4 broadcast an interview about the ozone hole on 2025 March 14. This is on BBC Sounds online

A 2024 paper on the biological effects of recent ozone depletion attracted media attention, but failed to present ozone data from 1990-2000. This would have shown a similar late spring warming to those of recent years during several consecutive years in the 1990s as in the image at right. Overall there is a steadily later spring warming.

An interview for a Glasgow Science Centre podcast

I wrote an essay on the ozone hole for the National Library of Scotland (2019 August)

Susan Solomon wrote a commentary for Nature on The discovery of the ozone hole (2019 October)

A Paper by Susan Solomon et al provides further evidence that the ozone hole is recovering and links volcanic eruptions to enhanced ozone depletion (2016 June).

UNEP video describing the ozone layer 2015 July 19

A summary of the WMO/UN 2014 Ozone Assessment, the  Assessment for Decision-Makers was released on 2014 September 10.

Nature PastCast on the Ozone Hole 2013 May 17

NERC Planet Earth Podcast on the Ozone Hole 2011 November 22

A Paper by Murry Salby et al suggests that the ozone hole is recovering (2011).

Main presentation and secondary presentation given at the WMO ozone workshop held in 2011 February at Hradec Kralove.

An opinion piece by Jonathan Shanklin to mark the 25th anniversary of the ozone hole appeared in Nature on 2010 May 6.  

A revised edition of the BAS ozone pamphlet was published in 2010.

Timor Leste ratified the Montreal Protocol on 2009 September 16, making it the first environmental treaty to be ratified by all UN Member States

Upper stratospheric ozone recovering ? [SPIE news 2009 July 27]

Ozone and Cosmic Rays

BAS Scientific Report No 90: Measurements of atmospheric ozone at the Argentine Islands and Halley Bay, 1957-72

The paper on the discovery of ozone depletion in Antarctica is available as an abstract from Nature online.

Forty Years ' Research on Atmospheric Ozone at Oxford: a History. G M B Dobson 1968 (scanned by NOAA ESRL GMD)

Listen again to the BBC Radio 4 programme "The Reunion" broadcast on 2007 April 29, which brings together the discoverers of the ozone hole

Slides from talk given to the Royal Meteorological Society on 2006 October 18

Theory of the Dobson from the NOAA ESRL GMD (formerly CMDL)

Institute of Physics i-seminar on the ozone hole and climate change given on 2005 October 31

The NASA ozone hole watch page

Some links to other sources of ozone information (updated 2004 November 19).

BAS Press Release on 2005 September 14 on 20th Anniversary of ozone hole discovery: International Ozone Day

Royal Astronomical Society ozone fact sheet

The 2001 July edition of Weather included an article on the ozone hole entitled 'Back to basics:- The ozone hole'. This version is slightly revised and updated.

WMO Press Release on 2003 September 16 (Antarctic ozone hole unusually large)

BAS Press Release on 2003 September 12 (BA Festival of Science - The ozone hole)

Slides of talk 'The split Antarctic vortex - has it ever happened before ?' given at the RMS/ACSG meeting on 2003 August 29

Twenty Questions and Answers about the Ozone Layer - WMO/UNEP Scientific Assessment of Ozone Depletion 2002

Why does the ozone hole form over Antarctica?

BAS was involved in the QUOBI project in 2003 to contrast the ozone layer over the Arctic with that of the Antarctic.  Trial ozonesonde flights took place at Rothera in March and regular flights began at the end of June.  Animation of the ozonesonde flight results.

Institute of Physics awards BAS Scientists the Charles Chree Medal and Prize

SCI Press Release BAS Scientists Awarded Environment Medal. This is what the medal looks like.

Severe Arctic ozone depletion in 2000

BAS was involved in a big international collaboration to measure the ozone hole in 1999 September and October. Details of ape-gaia are on the project web page.

Statement on stratospheric Ozone and the Ozone Hole

The BAS press release of 1997 October 2 'Ozone hole starts to form in midwinter at sunlit edge of Antarctica'. A postscript image shows the calculated ozone depletion on 1994 July 23.

An ozone hole did not exist in 1956 (despite suggestions to the contrary) [updated 2002 October 14].

UK ozone information from the Met Office.

The ozone FAQ

Canadian Met Service ozone information

Somewhat related is the subject of nacreous clouds , which were widely seen over the UK on 1996 February 18 and over Scotland on 1999 November 30. Very low ozone values were recorded over the North Sea on the later occasion, more details are available from NASA-TOMS . This event was probably caused by a combination of stratospheric and tropospheric dynamics (the stratosphere was very cold), with ozone depletion playing a minor role. On 2000 January 29 nacreous clouds were again seen over large parts of the UK. Stratospheric analyses show temperatures over the UK below -75 deg C on that day and the day before. Martin Brown has compiled a page of further information and pictures of the display. Significant ozone depletions of up to 30% were seen in some areas of the Arctic during early March 2000. Further displays were seen from the UK in 2011, 2016 February, 2017 January and 2019 December.

---

Ozone bulletins

The BAS ozone bulletins contained the actual ozone values reported together with an analysis of the situation. These were distributed by email on request, but are now superceded by this web site.  The last email ozone bulletin was issued on 2002 May 28.  The final situation report of each season is archived for historical reference.

---

Ozone data

Please read this metadata description before asking any questions about the data. [updated 2025 February 4].
Two documents describe our standard operating procedures: The BAS Dobson Manual and the BAS ozone station instructions. A paper describing the stations, observing programs and reduction procedures is in preparation. Most of our data is available on line, however please note that this is provisional and likely to change without warning.  You must request permission to reproduce the data and we may be able to supply more suitable or more up to date material.  If data from Halley is used you must give the station name as Halley;  Halley Bay was a geographical feature that no longer exists.

Older data (1972 - 2011) has been recomputed and all the preliminary values are posted.   Some of the zenith sky regressions do not give a good fit and will be improved.  The direct sun measurements during this period are unlikely to change.

Provisional Dobson daily mean ozone values for 2025/2026 for Halley  [Updated 2026 March 30, see below for SAOZ] and Vernadsky.  [Updated 2026 May 11].  Note : The calibration of the current instruments is not yet fully determined as the instruments use ongoing solar measurements for in-situ calibration.  The manual Dobson at Halley was changed in 2012 February and required maintenance in 2013 August.  The zenith sky tables or other calibration values were last revised on 2018 February 4, but the daily means may still have errors up to 5%, particularly when ozone values or the solar elevation are low.  Halley has become a summer only station and there are no manual observations between 2017 February 15 and 2017 December 7, 2018 February 26 and 2018 December 10, 2019 February 16 and 2021 January 10 and since 2021 February 10.  The instrument calibration constants are being revised, so values given here may change.  The automated Dobson is likely to have larger errors as it has not been callibrated under low ozone conditions.  The instrument constants for Dobson 123 at Vernadsky were revised in 2019 October and may require further revision. The preliminary Halley and Vernadsky values should therefore be treated with some caution.  

Halley
Provisional daily mean ozone values for Halley in 2011/12 , 2012/13 , 2013/14 , 2014/15 , 2015/16 , 2016/17 , 2017/18 , 2018/19 , 2019/20 , 2020/21 , 2021/22 , 2022/23 , 2023/24 , 2024/25 , 2025/26 using Dobson 31 in manual operation.
Provisional daily mean ozone values for Halley in 2005/06 , 2006/07 , 2007/08 , 2008/09 , 2009/10 , 2010/11 , 2011/12 using Dobson 73 in manual mode. 2017/18 , 2018/19 , 2019/20 , 2020/21 , 2021/22 , 2022/23 , 2023/24 , 2025/26 using Dobson 73 in auto mode.
Provisional daily mean ozone values for Halley in 1991/92 , 1992/93 , 1993/94 , 1994/95 , 1995/96 , 1996/97 , 1997/98 , 1998/99 , 1999/00 , 2000/01 , 2001/02 , 2002/03 , 2003/04 , 2004/05 , 2005/06 using Dobson 103.
Provisional daily mean ozone values for Halley in 1981/82 , 1982/83 , 1983/84 , 1984/85 , 1985/86 , 1986/87 , 1987/88 , 1988/89 , 1989/90 , 1990/91 , 1991/92 using Dobson 123.
Provisional daily mean ozone values for Halley in 1972/73 , 1973/74 , 1974/75 , 1975/76 , 1976/77 , 1977/78 , 1978/79 , 1979/80 , 1980/81 , 1981/82 using Dobson 31.

Provisional individual ozone values for Halley in 2011/12 , 2012/13 , 2013/14 , 2014/15 , 2015/16 , 2016/17 , 2017/18 , 2018/19 , 2019/20 , 2020/21 , 2021/22 , 2022/23 , 2023/24 , 2024/25 , 2025/26 using Dobson 31 in manual operation.
Provisional individual ozone values for Halley in 2005/06 , 2006/07 , 2007/08 , 2008/09 , 2009/10 , 2010/11 , 2011/12 with Dobson 73 in manual mode, 2017/18 , 2018/19 , 2019/20 , 2020/21 , 2021/22 , 2022/23 , 2023/24 , 2025/26 using Dobson 73 in auto mode.
Provisional individual ozone values for Halley in 1991/92 , 1992/93 , 1993/94 , 1994/95 , 1995/96 , 1996/97 , 1997/98 , 1998/99 , 1999/00 , 2000/01 , 2001/02 , 2002/03 , 2003/04 , 2004/05 , 2005/06 using Dobson 103.
Provisional individual ozone values for Halley in 1981/82 , 1982/83 , 1983/84 , 1984/85 , 1985/86 , 1986/87 , 1987/88 , 1988/89 , 1989/90 , 1990/91 , 1991/92 using Dobson 123.
Provisional individual ozone values for Halley in 1972/73 , 1973/74 , 1974/75 , 1975/76 , 1976/77 , 1977/78 , 1978/79 , 1979/80 , 1980/81 , 1981/82 using Dobson 31.

Faraday/Vernadsky
Provisional daily mean ozone values for Vernadsky in 2004/05 , 2005/06 , 2006/07 , 2007/08 , 2008/09 , 2009/10 , 2010/11 , 2011/12 , 2012/13 , 2013/14 , 2014/15 , 2015/16 , 2016/17 , 2017/18 , 2018/19 , 2019/20 , 2020/21 , 2021/22 , 2022/23 , 2023/24 , 2024/25 , 2025/26 using Dobson 123.
Provisional daily mean ozone values for Vernadsky in 1983/84 , 1984/85 , 1985/86 , 1986/87 , 1987/88 , 1988/89 , 1989/90 , 1990/91 , 1991/92 , 1992/93 , 1993/94 , 1994/95 , 1995/96 , 1996/97 , 1997/98 , 1998/99 , 1999/00 , 2000/01 , 2001/02 , 2002/03 , 2003/04 , 2004/05 using Dobson 31.
Provisional daily mean ozone values for Vernadsky in 1971/72 , 1972/73 , 1973/74 , 1974/75 , 1975/76 , 1976/77 , 1977/78 , 1978/79 , 1979/80 , 1980/81 , 1981/82 , 1982/83 , 1983/84 , 1984/85 using Dobson 73.

Provisional individual ozone values for Vernadsky in 2004/05 , 2005/06 , 2006/07 , 2007/08 , 2008/09 , 2009/10 , 2010/11 , 2011/12 , 2012/13 , 2013/14 , 2014/15 , 2015/16 , 2016/17 , 2017/18 , 2018/19 , 2019/20 , 2020/21 , 2021/22 , 2022/23 , 2023/24 , 2024/25 , 2025/26 using Dobson 123.
Provisional individual ozone values for Vernadsky in 1983/84 , 1984/85 , 1985/86 , 1986/87 , 1987/88 , 1988/89 , 1989/90 , 1990/91 , 1991/92 , 1992/93 , 1993/94 , 1994/95 , 1995/96 , 1996/97 , 1997/98 , 1998/99 , 1999/00 , 2000/01 , 2001/02 , 2002/03 , 2003/04 , 2004/05 using Dobson 31.
Provisional individual ozone values for Vernadsky in 1971/72 , 1972/73 , 1973/74 , 1974/75 , 1975/76 , 1976/77 , 1977/78 , 1978/79 , 1979/80 , 1980/81 , 1981/82 , 1982/83 , 1983/84 , 1984/85 using Dobson 73.

Provisional Dobson monthly mean ozone values for Faraday/Vernadsky between 1957 and 2025 January and Halley between 1956 and 2026 February, augmented with satellite data. 
Monthly mean satellite ozone values for Halley from 2004 October to 2026 February.  Note the satellite season lasts longer into April and starts earlier in August than do Dobson measurements.  Overall there is good agreement between the two datasets, so the satellite data may be used to fill Dobson data gaps.
Provisional monthly minimum ozone values for Faraday/Vernadsky between 1972 and 2025 January and Halley between 1956 and 2026 February, augmented with satellite estimates.
Mean daily ozone values for the period 1957 - 1972 for Faraday and Halley. [NB: not corrected to Bass-Paur]
Daily ozone values for the period 1957 - 1973 for Faraday and Halley. [Revised to Bass-Paur]
Provisional Halley SAOZ total column nitrogen dioxide and ozone: 2013 [processing revised 2013 November 22] , 2014 , 2015 , 2016 , 2021 , 2022 , 2023 , 2024 , 2025 , 2026 [updated  2026 May 11] and as real-time graphs showing current ozone and NO2 levels.  The SAOZ did not run from when the station closed before the 2018 winter until the 2021/22 summer.  There was no power during the 2022 and 2024 winters. The instrument stopped before the start of the 2025 winter. It was unresponsive for a short time in the autumn of 2026.

Temperature and Ozone graphs for Halley and Vernadsky/Faraday. [Updated 2021 December 14].  The historic period shown in the inline graphs is for 1957 - 1972.

Rothera
Ozone & nitrogen dioxide:  
SAOZ total column nitrogen dioxide and ozone: 1996 , 1997 , 1998 , 1999 , 2000 , 2001 , 2002 , 2003 , 2004 , 2005 , 2006 , 2007 and 2008 [to 2008 January 22].  
"New" SAOZ total column nitrogen dioxide and ozone: 2006 , 2007 , 2008 , 2009 , 2010 , 2011 , 2012 , 2013 , 2014 , 2015 , 2016 , 2017 , 2018 , 2019 , 2020 , 2021 , 2022 , 2023 , 2024 , 2025 , 2026 [updated 2026 May 11] and as real-time graphs showing current ozone and NO2 levels.  Data is missing between 2013 December 23 and 2014 January 6.  Data from 2017 January 6 to May 8 is likely to be revised as there were some issues with the instrument.  Some data in 2017 October and November, which show high standard deviation is also suspect, though in some cases this simply reflects large changes in ozone column during the day.  There are some shorter periods with missing data due to computer glitches.  These became more problematic in 2019 and no data was collected between 2019 January 18 and March 4.
Provisional monthly mean ozone values from 1996 to 2025 January.  Note that means for some months are based on partial data.
Ozonesondes:  During 2003 we carried out ozone sonde flights at Rothera as part of the QUOBI project.  Data from these flights is available in NASA-AMES format.  Animation of the ozonesonde flight results [note that although the ozone scale on these graphs reads nanobars, it should read mPa].
Bentham ozone. Provisional values for 1997 / 1998 / 1999 / 2000 / 2001 / 2003 / 2004 [updated 2004 November 5].  The Bentham instrument ran until 2012, but data from it has not been used to produce further ozone values.

King Edward Point, South Georgia
Provisional daily mean ozone values in 1971 , 1972 , 1973 , 1974 , 1975 , 1976 , 1977 , 1978 , 1979 , 1980 , 1981 , 1982
Provisional individual ozone values in 1971 , 1972 , 1973 , 1974 , 1975 , 1976 , 1977 , 1978 , 1979 , 1980 , 1981 , 1982

Cambridge
Some experimental data from an automated Dobson making zenith only observations is available, but this is not well calibrated, particularly when ozone amounts are above 350 DU and when the sun is low in the sky. Some preliminary data is now available, though there are some technical issues with the instrument leading to data gaps.  The instrument resumed operation in 2023 September after it underwent callibration at Hohenpeissenberg in 2023 July. The instrument constants have been adjusted and the zenith equations were revised in 2024 June, but there is still some uncertainty in the zenith sky equations. The electronics failed at the beginning of 2024 October, but have been repaired. The instrument is currently (2026 May) beging configured for automated direct sun observations. Trials of this started on April 30.
Provisional daily mean zenith ozone values for Cambridge in 2018/19 , 2019/20 , 2021/22 , 2022/23 , 2023/24 , 2024/25 , 2025/26 [updated 2026 May 11] using Dobson 103 in automode. Values are currently being over-estimated, by around 10%.
Provisional individual ozone values for Cambridge in 2018/19 , 2019/20 , 2021/22 , 2022/23 , 2023/24 , 2024/25 , 2025/26 using Dobson 103 in automode.

Some background information on Halley, Rothera and Faraday stations is available from BAS. Information about Vernadsky station is also available from the Ukrainian Antarctic Centre. Information about Vladimir Ivanovich Vernadsky

Some surface and upper air synoptic data is also available on line from our public data page.

Southern Hemisphere ozone hole movies for 1997/1998 , 1998/1999 , 1999/2000 , 2000/2001 , 2001/2002 , 2002/2003 , 2003/2004 , 2004/2005 , 2005 [TOMS], 2005/2006 , 2006/2007 , 2007/2008 , 2008/2009 , 2009/2010 , 2010/2011 , 2011/2012 , 2012/2013 , 2013/2014 , 2014/2015 , 2015/2016 , 2016/2017 , 2017/2018 , 2018/2019 , 2019/2020 [OMI], 2020/2021 , 2021/2022 [OMPS], 2022/2023 , 2023/2024 , 2024/2025 [OMI] , 2025/2026 [GOME 2, updated to 2026 April 30].  A short sequence of the 2001 ozone hole. A composite sequence of the 2022 and 2021 ozone holes running from 2022 June 21 to 2022 September 13 and 2021 September 14 to 2021 December 31.
Northern Hemisphere movies for 2000/2001 , 2001/2002 , 2002/2003 , 2003/2004 , 2004/2005 , 2005 [TOMS], 2005/2006 , 2006/2007 , 2007/2008 , 2008/2009 , 2009/2010 , 2010/2011 , 2011/2012 , 2012/2013 , 2013/2014 , 2014/2015 , 2015/2016 , 2016/2017 , 2017/2018 , 2018/2019 , 2019/2020 [OMI], 2020/2021 , 2021/2022 [OMPS], 2022/2023 , 2023/2024 , 2024/2025 [OMI] , 2025/2026 [GOME 2, updated to 2026 April 30].  A short sequence of ozone depletion during the 2002/03 northern winter showing the difference from the normal.
The annual ozone movies were about 7Mb and were compiled from daily TOMS images until the end of 2005; from 2005/06 until 2019/20 and again from 2022/23 they were compiled from OMI images. For 2020/21 and 2021/22 they used OMPS images and the annual file size was over 16Mb. The movies begin and end on the June solstice. Due to cutbacks at NOAA images from 2026 were not being stored in an accessible directory, so the moveis have switched to using GOME 2 from Temis.
Today's forecast Gome 2b Antarctic image
The current area of the hole and other latest details are available from the NOAA Climate Prediction Center.
Environment Canada have a set of daily maps showing both northern and southern ozone levels from a variety of sources.
The Sciamachy uv index from the ESA Tropospheric Emission Monitoring Internet Service.  Note that west longitude is negative when entering co-ordinates.

---

Contacts

Requests for permission to use this data or for further information should be sent to Jon Shanklin who maintains these pages.

---

NERC / BAS / MET

© Copyright Natural Environment Research Council - British Antarctic Survey 2026