Hottest day of each year from 1875
Some points about hot days
An annual maximum of less than 90F has happened just under 50% of the time since 1900 (90F is 32.2C). Since 1900,
34C or more has been seen 26 years, in (with the temperature being above 34 and beneath 35, 11 times: 1921, 1930, 1933, 1941, 1947, 1959, 1975, 1989, 2013, 2017, 2024), plus the 16 years below.
35C or more has been seen in 16 years from 1900 on (1906, 1911, 1923, 1932, 1948, 1957, 1976, 1990, 1995, 2003, 2006, 2015, 2018, 2019, 2020, 2022).
36C or more has been seen in 9 years (1911, 1932, 1990, 2003, 2006, 2015, 2019, 2020, 2022) and on 17 days; note how 6 of these 9 years have been since 2000. See list below
37C or more in five years (1990, 2003, 2019, 2020, 2022 [on two days]).
38C or more in three years (2003, 2019, 2022 [on two days]).
40C or more in one year (2022).
The summer of 1976 was exceptional in containing 5 consecutive days above 35C.
The 17 (possible) days on which 36C has been reached or exceeded are:
1 1911 36.1 22 July Epsom *
2 1911 36.7 9 August Raunds *
3 1932 36.1 19 August Halstead *
4 1990 36.6 2 August Barbourne *
5 1990 37.1 3 August Cheltenham
6 1990 36.1 4 August Brent Pelham*
7 2003 36.4 6 August Gravesend
8 2003 36.0 9 August London
9 2003 38.5 10 August Faversham *
10 2006 36.5 19 July Wisley
11 2015 36.7 1 July Heathrow
12 2019 38.7 25 July Cambridge
13 2020 37.8 31 July Heathrow
14 2020 36.4 7 August Heathrow & Kew
15 2020 36.2 11 August Charlwood
16 2022 38.1 18 July Pitsford
17 2022 40.3 19 July Coningsby
* Higher temperatures were reported in July 1911 but these are now considered unreliable; the recording conditions of all early records, inclusing those of 191 an 1932, do not compare with today's and might not be accurate. The August 1990 figure for Barbourne has been subject to scrutiny and might be unreliable - no other location that day reported a temperature over 36C. The 6 August Brent Pelham reading was out of line with neary stations and might not be accurate. Enfield recorded 36.9C on 9 August 2003, but the site was a rooftop and non-standard. The 2003 Faversham figure has been disputed, but it was definitely over 38 in the SE (38.1 Kew).
There is some uncertainty about earlier records for several reasons: non-standard screening of thermometers, the unreliability of Glaisher screens before Stevenson screens, non-standard positioning of sceens, the accuracy of thermometers, and the use of the Fahrenheit rather than Celsius scale. Before 1900, July 1868 was undoubtedly hot, and at some point probably exceeded 36; July 1808 saw some very hot days, and might have been very hot.
The earliest date on which 90F (32.2C) has been reached was on the 22 May 1922; the latest date was 19 September 1926.
All days over 36C have happened in July and August.
The lowest annual maximum is 27.8C, recorded in 1920 (Raunds) and 1962 (Writtle, Essex).
The hottest summer days occur when a very hot air mass (drawn up from the Continent on a southerly or southeaserly airflow) stagnates, with very little wind. Temperatures are likely to be higher after a lengthy spell of dry weather (e.g. 1911, 1976, 1990) because more of the sun's heat is used on heating the air rather than evaporating moisture from the ground. If there is wind, sheltered spots are favoured. This is one reason why London fares so well; in addition to any urban heating, it is sheltered from southerly winds by the North Downs. The anticyclone stops the hot air mixing vertically. Obviously the higher the angle of the sun the better (you can't hope for too much on Midwinter's Day!). It helps if the soil is dry, so that energy isn't "wasted" evaporating soil water.
Hottest day for each extended summer month and hottest days since 1900
May 32.8 (1922, London; 1944, London)
Jun 35.6 (1976, Southampton), 35.6 (1957 rounded from 35.55, 96F, London)
July 40.3 (2022, Coningsby, Lincs.)
August 38.5 (2003, Faversham; 38.1 Wisley)
September 35.6 (1906, Bawtry)
The history of the hottest day in Britain
2022 40.3C at Coningsby (Lincs.), 19 July
2019 38.7C reported at Cambridge Botanical Gardens, 25 July
2003 38.5C reported at Faversham, 10 August (disputed, 38.1 accepted)
1990 37.1C at Cheltenham, 3 August
1911 36.7C at Raunds and Canterbury, 9 August
1868 Before 1911 things are less clear because of concerns over the accuracy of measurements. 38.1C (100.5F) was reported as being recorded at Tonbridge on the 22nd, although the screening was nonstandard and this temperature is now recognised as being far too high. The temperature was more likely actually around 36.5C (97-98F).
Longest spells with consecutive days over 30C
1976 16
1947 14
2006 13 out of 14
2003 10
2018 9
1975, 1983, 1995 8
Hot weather across the world
The highest verified temperature recorded on Earth is 56.7 ºC at Furnace Creek, in Death Valley, California, USA, on 10 July 1913. A reading of 57.8 °C on 13 September 1922, in 'Azizya in Libya was decided to be unreliable in 2012. If the Furnace Creek record is subsequently rejected, as is possible, the record will be 54.0 (Death Valley on 20 June 2013, and in Mitribah, Kuwait, on 21 July 2016).
The highest temperature recorded in Europe is 48.0, at Athens (Greece) on 10 July 1977. The record for France is 46.0 (Verargies, Hérault, 28 June 2019), the Netherlands 40.7 (Gilze en rijen, 25 July 2019), and Spain 47.6 (La Rambla, Cordoba, on 14 August 2021).
The highest temperature recorded in the Republic of Ireland is 33.3ºC at Kilkenny Castle on 26 June 1887. In the twentieth centure it was 32.5ºC at Boora (Co Offaly) on 29 June 1976, and more recently we have seen 33.0ºC at Phoenix Park (Dublin) on 18 July 2022.
The hottest days in Britain from 1875
1875 30.1 Hillington (Norfolk) 16 August
1876 35.0 Cambridge 14 August
1877 29.7 Stratfield Turgis (Hants.) 18 June
1878 33.9 Llandudno 27 June
1879 26.8 Hillington (Norfolk) 29 July
1880 30.7 Loughborough (Leics.) 4 September
1881 35.0 Camden Square 15 July
1882 29.2 Portsmouth 6 August
1883 28.7 Norwood (London), Tunbridge Wells (Kent) 29 June
1884 34.1 Hillington (Norfolk) 11 August
1885 33.3 Southampton 26 July (34.7 Osborne (IoW) on same date appears suspect)
1886 31.7 Southampton 4 July
1887 31.7 Cambridge 3 July
1888 31.1 Cambridge 25 June
1889 30.3 Regents Park (London) 1 August
1890 28.3 Llandovery (Dyfed) 6 September
1891 30.0 Loughborough (Leics.) 10 September
1892 29.4 Cambridge 3 July
1893 34.7 Wryde (Cambs.) 18 August
1894 30.6 Weston-super-Mare 1 July
1895 30.6 Stratfield Turgis (Hants.) 25, 27 September
1896 31.2 Norwood (London) 14 July
1897 32.2 Cambridge 5 August
1898 33.4 Norwood (London) 7 September
1899 32.4 Cambridge 25 August (33.3 Bramley on 15 August appears suspect)
1900 35.1 Cambridge 20 July
1901 33.3 Bawtry (South Yorks.), Colly Weston (Northants.) 19 July, Newton Rigg (Cumbria) 20 July
1902 31.9 Hereford 28 June
1903 31.1 Wryde (Cambridgeshire) 10 July
1904 32.2 Margate 4 August
1905 30.0 Bawtry (South Yorks.) 14 July
1906 35.6 Bawtry (South Yorks.) 1 September
1907 30.0 Lairg 16 July
1908 32.8 Dumfries 2 July
1909 33.3 Epsom 15 August
1910 28.9 Maidenhead 20 June
1911 36.7 Raunds, Canterbury 9 August
1912 32.8 Tottenham 12 July
1913 29.4 New Malden (London) 16 June
1914 32.2 Woking, New Malden, Wisley (Surrey) 1 July
1915 32.2 Cromer, Norwich 8 June
1916 30.0 Woking 30 July, Salisbury 31 July
1917 33.9 Reading, Little Massingham (Norfolk) 17 June
1918 33.9 Canterbury 22 August
1919 32.2 Raunds 11 September
1920 27.8 Raunds 17 June
1921 34.4 Woking, Halstead (Essex) 11 July
1922 32.8 Camden Square 22 May
1923 35.6 Camden Square 13 July
1924 32.2 Camden Square 12 July
1925 33.3 Hunstanton 22 July
1926 32.2 Camden Square 19 September
1927 29.4 Camden Square 16 June
1928 32.8 Camden Square, Newport (IOW) 15 July
1929 32.2 Camden Square, Margate 31 August; Newport (IOW) 5 September
1930 34.4 Camden Square 29 August
1931 28.3 Bromley 14 June
1932 36.1 London (several sites, inc. Camden & Regents Park), Halstead 19 August
1933 34.4 Margate, Cambridge 27 July
1934 33.3 Attenborough (Notts.) 11 July
1935 33.3 Attenborough (Notts.) 13 July
1936 31.7 Camden Square 20, 21 June
1937 33.3 Canterbury, Tunbridge Wells 7 August
1938 30.6 Camden Square, Reading 1 August
1939 32.2 Camden Square 7 June
1940 32.8 Cranwell (Lincs.) 9 June
1941 34.3 Camden Square 22 June
1942 33.9 Sprowston (Norfolk) 27 August
1943 33.9 Worcester, Croydon 31 July
1944 32.8 Tunbridge Wells, Horsham, London (Camden Square and Regents Park) 29 May; Long Sutton (Hants.) 30 May
1945 32.2 Norwich, Whitstable 15 July
1946 30.6 Camden Square and Kensington (London) 2 July, Finningley 12 July, Greenwich and Maldon 24 July
1947 34.4 Waddington (Lincs.), Camden Square and Kensington (London) 3 June
1948 35.0 Milford (Surrey) 28 July
1949 33.3 Worcester 12 July
1950 33.3 Camden Square 6 June
1951 30.0 Southend 28 July
1952 33.9 Jersey 1 July; 33.3 Camden Square, Heathrow, Southampton 1 July
1953 33.9 Camden Square 12 August
1954 30.6 Camden Square 1 September
1955 32.8 Jersey 21 August (32.2C Chivenor, Devon, on 23 August)
1956 30.0 Camden Square 26 July, and Jersey on 27 July
1957 35.6 Camden Square 29 June
1958 29.4 Paisley 4, 5 July; Leicester 8 July
1959 34.4 Cromer, Boxworth, and St James's Park 5 July
1960 30.6 Wyton (Cambs.) 18 June
1961 33.9 Regents Park, Camden Square, Gillingham 1 July
1962 27.8 Writtle (Essex) 3 September
1963 28.9 Littlehampton 22 July; Ceinws (Powys.) 29 July; Wisley, Gordon Castle (Gramp.) 30 July
1964 32.8 Cromer 26 August
1965 29.4 Camden Square London 14 May
1966 28.9 Southampton 9 June; Perth, Crossmyloof (Strathclyde) 21 July; Regents Park and Camden Square 20 August
1967 30.2 Watnall (Notts.) 17 July
1968 33.3 Camden Square 1 July
1969 32.8 Letchworth (Herts.) 16 July
1970 32.2 Aldenham (Herts.), Stratford-upon-Avon 7 July
1971 30.0 Kensington Palace and St Jame's Park (London) 11 July
1972 29.4 Perth 20 July
1973 32.1 Southampton 14 August
1974 28.0 Southampton 15 June
1975 34.2 Heathrow, Stanstead Abbotts (Herts.) 8 August
1976 35.9 Cheltenham 3 July
1977 30.0 Paisley, Glenlee (D. & G.) 7 July; Onich (Highland) 11 July
1978 28.8 Poolewe (Highland) 4 June
1979 30.4 Benson (Ox.) 27 July
1980 29.4 Cors Fochno (Dyfed) 4 June
1981 29.5 Kew 5 August
1982 30.7 Morley St. Botolph (Norf.) 3 August
1983 33.0 East Bergholt (Suffolk) 15 July, Hampton 16 July
1984 31.9 St Louis (Jersey) 20 Aug (31.7 Heathrow on 8 July)
1985 30.1 St Louis (Jersey) 13 July (29.8 Heathrow 25 July)
1986 32.0 Rustington (W. Sussex) 28 June
1987 30.2 Liphook (Hants.) 21 Aug
1988 30.2 Cheltenham (Glos.) 7 Aug
1989 34.4 Mickleham (Surr.) 22 July
1990 37.1 Cheltenham 3 Aug
1991 32.1 Cromer (Norf.) 11 July
1992 30.3 Malvern 29 June
1993 29.7 East Bergholt (Suff.) 4 July
1994 33.4 Morley St Botolph (Norfolk) 12 July
1995 35.2 Boxworth (Cambs.) 1 Aug
1996 33.2 Boxworth (Cambs.) 22 July
1997 33.2 Writtle (Essex) 9 August
1998 32.2 Gravesend 10 August
1999 32.7 Heathrow 1 August, Honington (East Anglia) 2 August
2000 32.8 Coltishall (Norfolk) 19 June
2001 32.2 Northolt (London) 26 June
2002 32.6 Northolt (London) 29 July
2003 38.5 Brogdale, near Faversham (Kent) 10 August; debated, and 38.1C at Kew is more reliable
2004 31.5 Northolt (London) 8 August
2005 32.6 Heathrow 19 June
2006 36.5 Wisley (Surrey) 19 July
2007 30.1 Terrington St. Clement, Wisbech (Norfolk) and Cambridge Botannical Gardens 5 August
2008 30.2 Cambridge (NIAB HQ) 28 July
2009 31.8 Wisley (Surrey) 30 June
2010 31.7 Gravesend 9 July
2011 33.1 Gravesend 27 June
2012 32.4 Cavendish (Suffolk) 18 August
2013 34.1 Heathrow 1 August
2014 32.3 Swancombe Marsh (Kent) 18 July
2015 36.7 Heathrow 1 July
2016 35.2 St Hellier, Jersey 19 July (34.4 Gravesend 13 September)
2017 34.5 Heathrow 21 June
2018 35.6 Felsham (Suffolk) 27 July
2019 38.7 Cambridge Botannical Gardens 25 July
2020 37.8 Heathrow 31 July
2021 32.2 Heathrow 20 July
2022 40.3 Coningsby (Lincs.) 19 July
2023 33.2 Kew Gardens 9 September
2024 34.8 Cambridge 12 August (so far)