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 2025 heatwaves have occurred on 40 occasions between June and September.

Month:	June	July	August	September	Total
No. of heatwaves that began in the month:	9	20	10	1 (in 2023)	40
No. of heatwave days in the month:	33	97	60	6	196
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 1 July 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 1 July 2025


Each year in the 10-year period 2016-2025 experienced a heatwave; previously heatwaves had never occurred in more than two consecutive years, namely 1975-1976 and in 1989-1990. In the 56-year period 1970-2025 heatwaves occurred in 25 of the years, 16 of them since 2000. The period 2001-2025 saw 123 of the 196 heatwave days recorded since 1970.

Each year in the 10-year period 2016-2025 experienced a heatwave; previously heatwaves had never occurred in more than two consecutive years, namely 1975-1976 and in 1989-1990.

In the 56-year period 1970-2025 heatwaves occurred in 25 of the years, 16 of them since 2000. The period 2001-2025 saw 123 of the 196 heatwave days recorded since 1970.