Heathrow Threshold Days by Year (UKE00107650)
12 fixed thresholds counted per year at Heathrow (UKE00107650): hot days, frost, tropical nights and heavy rain, with the most days in a year.
Key Facts for Heathrow Thresholds
- Heathrow: nights with a minimum temperature at or below 0 C (32 F) in 67 years, most in 1963 with 78.
- Heathrow: days with 10 mm (0.39 in) or more of precipitation in 67 years, most in 2002 with 26.
- Heathrow: days with 25 mm (0.98 in) or more of precipitation in 56 years, most in 1967 with 3.
- Heathrow: days with a maximum temperature at or above 30 C (86 F) in 46 years, most in 1976 with 20.
- 12 fixed thresholds have at least one qualifying day at Heathrow.
Days at or above 30 C (86 F)
46 years with a qualifying day| Year | Days | Decade average |
|---|---|---|
| 1961 | 3 | 1.6 |
| 1964 | 1 | 1.6 |
| 1967 | 1 | 1.6 |
| 1968 | 1 | 1.6 |
| 1969 | 2 | 1.6 |
| 1970 | 2 | 7.8 |
| 1973 | 3 | 7.8 |
| 1975 | 6 | 7.8 |
| 1976 | 20 | 7.8 |
| 1983 | 9 | 5.3 |
| 1984 | 3 | 5.3 |
| 1986 | 3 | 5.3 |
| 1989 | 6 | 5.3 |
| 1990 | 9 | 5.6 |
| 1992 | 1 | 5.6 |
| 1994 | 6 | 5.6 |
| 1995 | 16 | 5.6 |
| 1996 | 6 | 5.6 |
| 1997 | 3 | 5.6 |
| 1998 | 1 | 5.6 |
| 1999 | 3 | 5.6 |
| 2000 | 2 | 5.6 |
| 2001 | 6 | 5.6 |
| 2002 | 2 | 5.6 |
| 2003 | 9 | 5.6 |
| 2004 | 2 | 5.6 |
| 2005 | 6 | 5.6 |
| 2006 | 15 | 5.6 |
| 2009 | 3 | 5.6 |
| 2010 | 2 | 5.5 |
| 2011 | 2 | 5.5 |
| 2012 | 3 | 5.5 |
| 2013 | 6 | 5.5 |
| 2014 | 1 | 5.5 |
| 2015 | 3 | 5.5 |
| 2016 | 5 | 5.5 |
| 2017 | 7 | 5.5 |
| 2018 | 18 | 5.5 |
| 2019 | 8 | 5.5 |
| 2020 | 10 | 12.4 |
| 2021 | 6 | 12.4 |
| 2022 | 11 | 12.4 |
| 2023 | 10 | 12.4 |
| 2024 | 5 | 12.4 |
| 2025 | 14 | 12.4 |
| 2026 | 31 | 12.4 |
| Year | First date | Last date |
|---|---|---|
| 1961 | 1961-06-29 | 1961-08-28 |
| 1964 | 1964-08-25 | 1964-08-25 |
| 1967 | 1967-07-16 | 1967-07-16 |
| 1968 | 1968-06-30 | 1968-06-30 |
| 1969 | 1969-07-15 | 1969-08-10 |
| 1970 | 1970-06-09 | 1970-07-06 |
| 1973 | 1973-08-13 | 1973-08-15 |
| 1975 | 1975-07-28 | 1975-08-07 |
| 1976 | 1976-06-07 | 1976-08-23 |
| 1983 | 1983-07-10 | 1983-08-18 |
| 1984 | 1984-07-07 | 1984-07-27 |
| 1986 | 1986-06-26 | 1986-06-29 |
| 1989 | 1989-06-19 | 1989-07-23 |
| 1990 | 1990-07-14 | 1990-08-28 |
| 1992 | 1992-06-28 | 1992-06-28 |
| 1994 | 1994-07-10 | 1994-08-02 |
| 1995 | 1995-06-27 | 1995-08-20 |
| 1996 | 1996-06-05 | 1996-08-18 |
| 1997 | 1997-08-07 | 1997-08-18 |
| 1998 | 1998-08-09 | 1998-08-09 |
| 1999 | 1999-07-30 | 1999-08-01 |
| 2000 | 2000-06-17 | 2000-06-18 |
| 2001 | 2001-06-25 | 2001-08-24 |
| 2002 | 2002-07-28 | 2002-08-16 |
| 2003 | 2003-07-14 | 2003-08-11 |
| 2004 | 2004-06-07 | 2004-08-07 |
| 2005 | 2005-05-27 | 2005-08-31 |
| 2006 | 2006-06-12 | 2006-09-11 |
| 2009 | 2009-06-29 | 2009-07-01 |
| 2010 | 2010-06-26 | 2010-07-08 |
| 2011 | 2011-06-26 | 2011-08-02 |
| 2012 | 2012-07-24 | 2012-08-18 |
| 2013 | 2013-07-12 | 2013-07-31 |
| 2014 | 2014-07-17 | 2014-07-17 |
| 2015 | 2015-06-29 | 2015-08-21 |
| 2016 | 2016-07-18 | 2016-09-12 |
| 2017 | 2017-06-16 | 2017-07-06 |
| 2018 | 2018-06-30 | 2018-08-06 |
| 2019 | 2019-06-28 | 2019-08-26 |
| 2020 | 2020-06-23 | 2020-08-11 |
| 2021 | 2021-07-17 | 2021-09-07 |
| 2022 | 2022-06-16 | 2022-08-13 |
| 2023 | 2023-06-09 | 2023-09-09 |
| 2024 | 2024-06-25 | 2024-08-11 |
| 2025 | 2025-06-18 | 2025-08-14 |
| 2026 | 2026-05-23 | 2026-08-13 |
Every Fixed Threshold
| Threshold | Years with a qualifying day | Most days in a year | Year | Latest year days |
|---|---|---|---|---|
| 30 C (86 F): Days | 46 | 20 | 1976 | 31 |
| 35 C (95 F): Days | 9 | 5 | 2020 | 5 |
| 40 C (104 F): Days | 1 | 1 | 2022 | 1 |
| 90 F (32.2 C): Days | 27 | 9 | 1976 | 15 |
| 100 F (37.8 C): Days | 4 | 1 | 2003 | 1 |
| 0 C (32 F): Ice days (max | 22 | 12 | 1963 | 1 |
| 0 C (32 F): Frost days (min | 67 | 78 | 1963 | 10 |
| -10 C (14 F): Days with min | 4 | 5 | 1963 | 1 |
| 20 C (68 F): Tropical nights (min | 15 | 4 | 1976 | 6 |
| 10 mm (0.39 in): Days with 10 mm or more rain | 67 | 26 | 2002 | 7 |
| 25 mm (0.98 in): Days with 25 mm or more rain | 56 | 3 | 1967 | 1 |
| 50 mm (1.97 in): Days with 50 mm or more rain | 9 | 1 | 1962 | 1 |
Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1961.
Download the Data
Source: NOAA National Centers for Environmental Information, Global Historical Climatology Network Daily (GHCN-Daily). Records are computed by World Extreme Weather Monitor and are not official NOAA products. (US Government open data (NOAA NCEI)) Data as of 2026-10-17 (17 October 2026). Threshold counts are computed by this site.
Data as of . Last revised (2026-10-17).