Extreme weather recordings

Extreme weather at Rothamsted

Last updated 1st May 2024.

Rothamsted Research at Harpenden has the longest run of freely-available daily weather data in England and has been sending returns to the UK Meteorological Office since at least 1878. In 2017, Rothamsted was recognised by the World Meteorological Organization (WMO) as a Centennial Observation Station being one of the relatively small number of sites in the UK that has been recording reliable observations continuously for more than 100 years. Rainfall has been measured daily for more than 160 years, since 1853, using a 5-inch gauge and a much larger, and unusual, 1,000th of an acre gauge. Subsequently, other weather variables were added to the list including temperature from about 1878, sunshine hours from 1890, and wind force/speed from 1915. Weather variables were recorded manually until the end of 2003; an automatic data logger was installed to record the data electronically from 1st January 2004*.

The Rothamsted weather records reflect many of the memorable national weather events such as the heatwaves of 1976, 2018 and 2022, the severe winters of 1947 and 1963, the heavy rainfall of December 2015, and the drought of 1921. The highs and lows include:

• Extreme Days
• Extreme Months
• Extreme Years
• Extreme Decades

Extreme Days Back to top

Hottest day

The highest temperature at Rothamsted (Harpenden), since records began in January 1878, was 38.4 C on Tuesday 19th July 2022 (this beats the previous record at Harpenden of 36.7 °C on July 25th 2019). July 19th 2022 was also the record hottest day at the Rothamsted weather stations at Woburn in Bedfordshire, with 39.5 °C, and at Brooms Barn in Suffolk, with 38.8 °C.

The highest daily maximum air temperature recorded for every day of the year since records began in 1878 are available as a downloadable Excel file, click here : Daily Maximum Temperatures recorded at Rothamsted for each day of the year since records began in 1878 Seven of these are in 2022 so far; the highest number for one year was 15 record days in 2015; in 1957 there were 12 hottest days; in 1893 and 1906 there were 9 hottest days.

The 2022 European heat wave led to the hottest summer on record in Europe since at least 1540. Several weather records were broken in the United Kingdom, including the UK's highest recorded temperature of 40.3 C at Coningsby in Lincolnshire - the first time 40C has been exceeded in the UK since records began (surpassing the previous record of 38.7 °C in Cambridge on 25th July 2019).

Coldest day

The lowest temperature, since records began in January 1878, was -17.0 °C on 13th December 1981.

The winter of 1981-82 in the United Kingdom was called "The Big Snow of 1982" by the press (Wikipedia).

Original record sheet relating to the coldest day

Wettest day

The wettest day, since records began in February 1853, with 3.238 inches (82.2mm) rain was 26th June 1888.

The Times reported on July 12 1888: “Extraordinary weather for the time of year is reported from various parts of the country" with snow in the summer!

Original record sheets relating to the wettest day

The ten warmest days since records began in January 1878.

The ten warmest days (maximum temperature reached in that day) at Rothamsted have all been since 1990, nine of them in the 21st century.

The ten coldest days since records began in January 1878.

The ten coldest days (minimum temperatures) at Rothamsted were all pre-1982, with more than half of them pre-1900.

Extreme months Back to top

The hottest and coldest months since records began in January 1878.

There are various ways to look at this data, this table shows just a few options.
Eight of the warmest months were since 2000, whilst only one of the coldest months was after 2000.The highest maximum mean monthly temperature ever recorded was July 2006 and the coldest minimum mean month ever recorded was February 1947.

Bold indicates a record in the last year.

The wettest and driest months since records began in January 1853.

Half of the wettest months were since 2000. The driest months were all before 1990, with the exception of April 2021, five of the driest were in the 19th Century.

The sunniest and dullest months since records began in January 1890.

Five of the sunniest months were between 1975 and 1997, whilst seven of the dullest months were between and 1956 and 1996.