Heatwaves in Reading

Definition of a heatwave

In Reading and the surrounding area, the official definition of a heatwave is a spell of three days or more, each of which has a maximum temperature of 28 °C or above.

Occurrences since 1970

The University's weather station was moved to its current location in January 1970. Between 1970 and 2024 heatwaves have occurred on 38 occasions between June and September.

Month:	June	July	August	September	Total
No. of heatwaves that began in the month:	7	19	10	1 (in 2023)	37
No. of heatwave days in the month:	26	93	59	6	184
Highest temperature each month in a heatwave:	34.0 °C (June 1976)	37.6 °C (July 2022)	36.4 °C (August 2003)	31.4 °C (September 2023)


Some statistics: Earliest day forming part of a heatwave: 9 June 1970 Latest day that was part of a heatwave: 9 September 2023 Most heatwave days in a year: 20 (in both 1995 and 2018) Longest heatwave: 16 days 23 June - 8 July 1976 Most heatwaves in a year: 4 (in both 1995 and 2018) Fewest heatwaves in a year 0 (in each of 1971-1972, 1974, 1977-1982, 1984-1985, 1987-1988, 1991-1994, 1996-1998, 2000, 2002, 2004-2005, 2010-2012 and 2014-2015)	Both graphs updated to 31 May 2025

Some statistics:

Earliest day forming part of a heatwave:: 9 June 1970
Latest day that was part of a heatwave:: 9 September 2023
Most heatwave days in a year:: 20 (in both 1995 and 2018)
Longest heatwave: 16 days: 23 June - 8 July 1976
Most heatwaves in a year:: 4 (in both 1995 and 2018)
Fewest heatwaves in a year: 0 (in each of 1971-1972, 1974, 1977-1982, 1984-1985, 1987-1988, 1991-1994, 1996-1998, 2000, 2002, 2004-2005, 2010-2012 and 2014-2015)

Both graphs updated to 31 May 2025


Each year in the 9-year period 2016-2024 experienced a heatwave; previously heatwaves had never occurred in more than two consecutive years, namely 1975-1976 and in 1989-1990. In the 54-year period 1970-2024 heatwaves occurred in 24 of the years, 14 of them since 2000. The period 2001-2024 saw 115 of the 188 heatwave days recorded since 1970.

Each year in the 9-year period 2016-2024 experienced a heatwave; previously heatwaves had never occurred in more than two consecutive years, namely 1975-1976 and in 1989-1990.

In the 54-year period 1970-2024 heatwaves occurred in 24 of the years, 14 of them since 2000. The period 2001-2024 saw 115 of the 188 heatwave days recorded since 1970.