See more information about this guidance

Research and analysis

A4: Rural background concentrations of ozone (O3) in England, 1987 to 2024

Updated 1 December 2025
Download CSV 7.47 KB

year measure value
1987 Annual average maximum daily 8-hour mean O3 concentration 56.1958322810192
1988 Annual average maximum daily 8-hour mean O3 concentration 63.6740120912583
1989 Annual average maximum daily 8-hour mean O3 concentration 66.7820862386868
1990 Annual average maximum daily 8-hour mean O3 concentration 69.0090526042944
1991 Annual average maximum daily 8-hour mean O3 concentration 67.5090647754196
1992 Annual average maximum daily 8-hour mean O3 concentration 66.925400004445
1993 Annual average maximum daily 8-hour mean O3 concentration 64.1228786974178
1994 Annual average maximum daily 8-hour mean O3 concentration 69.2194509663439
1995 Annual average maximum daily 8-hour mean O3 concentration 69.8537820350031
1996 Annual average maximum daily 8-hour mean O3 concentration 66.0445990777601
1997 Annual average maximum daily 8-hour mean O3 concentration 65.9271091380184
1998 Annual average maximum daily 8-hour mean O3 concentration 66.7536380580229
1999 Annual average maximum daily 8-hour mean O3 concentration 71.3998485231178
2000 Annual average maximum daily 8-hour mean O3 concentration 66.8667948330435
2001 Annual average maximum daily 8-hour mean O3 concentration 66.1832355723825
2002 Annual average maximum daily 8-hour mean O3 concentration 66.9609385037934
2003 Annual average maximum daily 8-hour mean O3 concentration 73.340827790841
2004 Annual average maximum daily 8-hour mean O3 concentration 71.6374870065958
2005 Annual average maximum daily 8-hour mean O3 concentration 69.7079889646969
2006 Annual average maximum daily 8-hour mean O3 concentration 73.7136627933317
2007 Annual average maximum daily 8-hour mean O3 concentration 67.1231779085362
2008 Annual average maximum daily 8-hour mean O3 concentration 68.2073208153939
2009 Annual average maximum daily 8-hour mean O3 concentration 66.5495631071086
2010 Annual average maximum daily 8-hour mean O3 concentration 66.5295678511618
2011 Annual average maximum daily 8-hour mean O3 concentration 66.8744812263178
2012 Annual average maximum daily 8-hour mean O3 concentration 64.4012367998204
2013 Annual average maximum daily 8-hour mean O3 concentration 67.4370181507237
2014 Annual average maximum daily 8-hour mean O3 concentration 68.7675323343962
2015 Annual average maximum daily 8-hour mean O3 concentration 70.3494330481011
2016 Annual average maximum daily 8-hour mean O3 concentration 66.1762383132998
2017 Annual average maximum daily 8-hour mean O3 concentration 68.3738345816187
2018 Annual average maximum daily 8-hour mean O3 concentration 72.4095159634489
2019 Annual average maximum daily 8-hour mean O3 concentration 71.817000400399
2020 Annual average maximum daily 8-hour mean O3 concentration 72.6692957869935
2021 Annual average maximum daily 8-hour mean O3 concentration 70.3300089579977
2022 Annual average maximum daily 8-hour mean O3 concentration 74.3056700403085
2023 Annual average maximum daily 8-hour mean O3 concentration 73.3364208561571
2024 Annual average maximum daily 8-hour mean O3 concentration 71.7144511879476
1987 95% confidence interval upper bound 74.5401963908724
1988 95% confidence interval upper bound 71.21238473229664
1989 95% confidence interval upper bound 74.80402209779369
1990 95% confidence interval upper bound 75.61463862914573
1991 95% confidence interval upper bound 74.95505708288685
1992 95% confidence interval upper bound 74.86349778355986
1993 95% confidence interval upper bound 72.26774882041538
1994 95% confidence interval upper bound 74.51863556372189
1995 95% confidence interval upper bound 75.28449870123993
1996 95% confidence interval upper bound 70.56802178137495
1997 95% confidence interval upper bound 70.35249898367667
1998 95% confidence interval upper bound 70.91502346105435
1999 95% confidence interval upper bound 75.07291745154032
2000 95% confidence interval upper bound 70.43044088822212
2001 95% confidence interval upper bound 69.99514059496288
2002 95% confidence interval upper bound 70.3149206344626
2003 95% confidence interval upper bound 77.11546939101946
2004 95% confidence interval upper bound 74.24676361141533
2005 95% confidence interval upper bound 73.270513425801
2006 95% confidence interval upper bound 77.63280939649326
2007 95% confidence interval upper bound 70.06031376392872
2008 95% confidence interval upper bound 71.01811703272006
2009 95% confidence interval upper bound 70.03403439977315
2010 95% confidence interval upper bound 70.47725118061184
2011 95% confidence interval upper bound 70.15485186849325
2012 95% confidence interval upper bound 67.39336354251351
2013 95% confidence interval upper bound 70.0979104092008
2014 95% confidence interval upper bound 71.95974723604337
2015 95% confidence interval upper bound 72.89857113085036
2016 95% confidence interval upper bound 68.3509763455663
2017 95% confidence interval upper bound 71.0878589139653
2018 95% confidence interval upper bound 74.87928484010448
2019 95% confidence interval upper bound 74.55922772264144
2020 95% confidence interval upper bound 75.15504887557744
2021 95% confidence interval upper bound 72.04751146261785
2022 95% confidence interval upper bound 76.37156811259653
2023 95% confidence interval upper bound 75.697169064731
2024 95% confidence interval upper bound 73.20597412101873
1987 95% confidence interval lower bound 37.851468171166005
1988 95% confidence interval lower bound 56.13563945021996
1989 95% confidence interval lower bound 58.76015037957991
1990 95% confidence interval lower bound 62.40346657944307
1991 95% confidence interval lower bound 60.06307246795235
1992 95% confidence interval lower bound 58.987302225330126
1993 95% confidence interval lower bound 55.97800857442023
1994 95% confidence interval lower bound 63.92026636896591
1995 95% confidence interval lower bound 64.42306536876629
1996 95% confidence interval lower bound 61.52117637414525
1997 95% confidence interval lower bound 61.501719292360114
1998 95% confidence interval lower bound 62.59225265499145
1999 95% confidence interval lower bound 67.72677959469527
2000 95% confidence interval lower bound 63.30314877786488
2001 95% confidence interval lower bound 62.37133054980212
2002 95% confidence interval lower bound 63.6069563731242
2003 95% confidence interval lower bound 69.56618619066255
2004 95% confidence interval lower bound 69.02821040177628
2005 95% confidence interval lower bound 66.14546450359279
2006 95% confidence interval lower bound 69.79451619017013
2007 95% confidence interval lower bound 64.1860420531437
2008 95% confidence interval lower bound 65.39652459806774
2009 95% confidence interval lower bound 63.065091814444045
2010 95% confidence interval lower bound 62.58188452171176
2011 95% confidence interval lower bound 63.59411058414235
2012 95% confidence interval lower bound 61.409110057127286
2013 95% confidence interval lower bound 64.77612589224661
2014 95% confidence interval lower bound 65.57531743274902
2015 95% confidence interval lower bound 67.80029496535185
2016 95% confidence interval lower bound 64.00150028103332
2017 95% confidence interval lower bound 65.65981024927208
2018 95% confidence interval lower bound 69.93974708679332
2019 95% confidence interval lower bound 69.07477307815655
2020 95% confidence interval lower bound 70.18354269840957
2021 95% confidence interval lower bound 68.61250645337756
2022 95% confidence interval lower bound 72.23977196802046
2023 95% confidence interval lower bound 70.97567264758321
2024 95% confidence interval lower bound 70.22292825487648