Cambridge Botanic Garden: hottest day on record 39.9 °C

Summary of the 1898–2026 period

The cambridge-botanic-garden station provides a continuous daily climate record from 1898-01-02 to 2026-06-17. Across this long series, the hottest day ever recorded is 39.9°C on 2022-07-20, followed closely by 38.7°C on 2019-07-26 and 38.0°C on 2022-07-19. These values confirm that the most extreme heat in Cambridge has occurred in the 21st century.

Looking at long-term averages, July is the warmest month with a mean daily maximum of 22.3°C, barely ahead of August at 22.2°C. The coolest month is January, with an average maximum of 7.0°C and an average minimum of 1.1°C. The annual mean maximum temperature across all years in the series is 14.7°C, but recent decades show higher values: for instance, 2006 reached 16.3°C, 2022 averaged 16.9°C, and 2025 reached 18.8°C.

Winter extremes are also notable: the coldest minimum ever recorded was -17.2°C in 1947, while more recently 2012 dropped to -13.6°C and 1981 to -14.5°C. These contrasts define Cambridge's continental-influenced climate within the East of England.

Maximum temperatures by month

July holds the absolute monthly maximum of 39.9°C, while August follows with 36.9°C. Interestingly, May and June share the same record maximum of 34.0°C, showing that late spring can occasionally bring intense heat. The daily average maximum peaks in July at 22.3°C, making it the climatological warmest month.

The 5 hottest days on record

The top five hottest days are dominated by extreme summer events: three of the five occurred in the 21st century, with 2022-07-20 and 2019-07-26 being the most intense. The 2003 heatwave and a 1990 event round out the list, showing that exceptional heat has always been part of Cambridge's climate, but the recent values are clearly higher.

Annual maximum temperatures

The chart shows the complete annual series. The table lists the most notable years; the full series comes from Met Office.

The annual maximum shows a clear upward shift: before 1990, only three years surpassed 35°C (1911, 1932, 1947). Since 1990, there have been seven such years, culminating in 39.9°C in 2022 and 38.7°C in 2019. The average annual maximum also rose from around 14°C in the early 1900s to 16.9°C in 2022 and 18.8°C in 2025, reflecting a general warming trend.

Frequently asked questions

What is the highest temperature ever recorded at Cambridge Botanic Garden?

The highest daily maximum is 39.9°C, recorded on 2022-07-20. This is the absolute record for the station's complete series from 1898 to 2026.

Which month has the warmest average maximum?

July has the highest average daily maximum at 22.3°C, closely followed by August at 22.2°C. June is third with 20.2°C.

What was the hottest summer period in terms of extreme days?

The most extreme period was July 2022, which produced the two highest temperatures on record: 39.9°C on 2022-07-20 and 38.0°C on 2022-07-19. The summer of 2003 also stands out with 36.9°C on 2003-08-11.

How does the 2022 heatwave compare to previous record years?

Before 2022, the highest temperature was 38.7°C on 2019-07-26, followed by 36.9°C in 2003 and 36.5°C in 1990. The 2022 record of 39.9°C surpasses all of them by more than 1°C.

What is the coldest minimum temperature ever measured at the station?

The lowest minimum temperature in the series is -17.2°C, recorded during 1947, which remains the most extreme cold event. More recent cold winters include -16.1°C in 1982 and -13.6°C in 2012.

Where exactly is the cambridge-botanic-garden station?

It is the AEMET station with code '00454' located at Cambridge University Botanic Garden. The data series runs from 1898-01-02 to 2026-06-17, providing a long and reliable record for eastern England.