Hottest day on record at Cambridge Botanic Garden

Summary of the record

Cambridge Botanic Garden is one of the reference Met Office stations for eastern England, and its daily archive runs from 2 January 1898 to 31 December 2025. Every figure on this page comes from that continuous daily record, which lets us rank individual days, months and years rather than relying on memory or on a handful of headline values.

The headline number is straightforward: 39.9°C on 20 July 2022. It is the highest maximum temperature ever logged at this station, and it sits above the previous extreme of 38.7°C reached on 26 July 2019. Those two dates are also the only occasions in the series on which the mercury passed 38°C, which shows just how unusual the most recent heat events have been for this part of the country.

Beyond the single record day, the monthly and yearly tables below show where the heat sits across the calendar. July is the month with the highest average daily maximum at 22.3°C, followed closely by August at 22.2°C, while the coldest monthly peak on average is January at 7.0°C. The annual tables reveal a long, slow drift: the yearly average of daily maxima was around 14°C for much of the twentieth century and has settled nearer 15°C to 17°C in recent decades.

Maximum temperatures by month

The table below summarises the record for each calendar month across the whole series: the average daily maximum, the highest maximum ever recorded in that month, and the average daily minimum.

July carries the highest monthly extreme of the year, 39.9°C, while June reaches 34.0°C and August tops out at 36.9°C. September is notable as well: its highest maximum of 33.9°C shows that heat has not always been confined to midsummer. At the other end of the scale, the highest maximum ever seen in January is 15.7°C and in December 16.0°C, so even midwinter can deliver a mild day, just never anything close to a summer value.

The five hottest days on record

These are the five highest daily maxima ever recorded at Cambridge Botanic Garden, with the minimum and the daily mean for each date.

Three of the five hottest days at this station fall in July, and two of those — 19 and 20 July 2022 — came back to back, with 38.0°C followed the next day by 39.9°C. The other two entries sit in August, on 11 August 2003 and 4 August 1990. On every one of these dates the minimum stayed at 16.6°C or above, which is why the daily mean in each case sits between 26.6°C and 29.4°C.

Yearly maximum temperatures

The complete year-by-year record for the station, listing the highest maximum of each year, the yearly average of daily maxima, and the lowest minimum recorded in that year. Years with no value are shown as not available in the period analysed.

2022 stands out with the highest yearly maximum of 39.9°C and the highest yearly average of daily maxima at 17.0°C, followed by 2025 at 18.7°C for the average and 33.1°C for the maximum. These two years also carry the mildest winters on the list in terms of the lowest minimum recorded: -2.0°C in 2025 and -3.4°C in 2020 and 2014. By contrast, the deepest cold in the series appears in the first half of the twentieth century, with -17.2°C in 1947, -16.1°C in 1963 and 1982, -15.6°C in 1920, and -14.5°C in 1981.

Frequently asked questions

When was the hottest day ever recorded at Cambridge Botanic Garden?

The hottest day was 20 July 2022, when the maximum reached 39.9°C. The minimum that night stayed at 18.9°C and the daily mean was 29.4°C. It is the highest maximum in the whole Met Office record for this station.

Which days come closest to that record?

The second-highest maximum was 38.7°C on 26 July 2019, followed by 38.0°C on 19 July 2022, 36.9°C on 11 August 2003 and 36.5°C on 4 August 1990. No other day in the series reached these levels.

Which month has the highest temperatures?

July has the highest average daily maximum of the year at 22.3°C and also the highest single-month extreme, 39.9°C. August is almost identical on average at 22.2°C and peaks at 36.9°C, while June averages 20.3°C with a highest maximum of 34.0°C.

Has the station ever recorded a maximum above 35°C?

Yes, on several occasions in the recent part of the series. The yearly records show 39.9°C in 2022, 38.7°C in 2019, 36.9°C in 2003, 36.5°C in 1990, 35.6°C in 2006, 35.6°C in 1932, 35.3°C in 1911, 35.1°C in 2020 and 35.0°C in 2015.

Which year had the highest average maximum temperature?

The yearly average of daily maxima was highest in 2025 at 18.7°C, followed by 1949 at 18.0°C, 2022 at 17.0°C, 2006 at 16.3°C and 2011 at 16.1°C. For most of the twentieth century the annual average sat around 14°C.

When did the coldest conditions at this station occur?

The lowest minimum on record at the station is -17.2°C, recorded during 1947. Other notably cold values include -16.1°C in 1963 and 1982, -15.6°C in 1920, and -14.5°C in 1981.