The 2021 Britain and Ireland heat wave was a period of unusually hot weather in July 2021 that led to record-breaking temperatures in the UK and Ireland.
On 21 July, temperatures reached 32.2 °C (90.0 °F) at Heathrow, London.[10] In Ireland, temperatures reached 30.8 °C (87.4 °F) at Mount Dillon, County Roscommon. In Northern Ireland a new record for maximum temperature was set, with 31.3 °C (88.3 °F) was reached at Castlederg, County Tyrone.[11]
Despite the extreme weather warning, the 2021 July heatwave was relatively mild in comparison to heatwaves in the UK and Ireland of previous and subsequent years, with heatwaves in previous years surpassing the maximum temperature of this heatwave, particularly in the south east.[12][13][14]