Northern Ireland won’t forget the July 2021 heatwave in a hurry. It included the all-time high temperature record for Northern Ireland, 31.3°C at Castlederg on the 21st, with several days exceeding 31C. It was hot and sunny.
Both Northern Ireland and Scotland recorded their third warmest July and saw 125% of the average sunshine amount. It was also drier than average, particularly for western counties of Scotland. With the hot weather also across Britain in the middle of the month, July 2021 was the joint fifth warmest July on record according to the UK Met Office.
It was also very warm by night which lifted the average minimum temperature. This was the joint second warmest for July. The ongoing heat by day and night lead to the first ever “Extreme Heat” warnings. For SW Britain and then Northern Ireland.
Met Office “The impacts of extreme heat can be many and varied. It can have health consequences, especially for those who are particularly vulnerable, and it can impact infrastructure, including transport and energy, as well as the wider business community. During hot weather we often see increased traffic near coastal areas, increased use of open water by the public, and an increase in wildfire risk.”
As our global climate warms these severe events will become more frequent and serious. Heatwaves are deadly and the UK is expected to see hotter & drier summers and more frequent & intense weather extremes. Clear information is needed to help people plan their daily and weekly lives.
Summer rainfall often falls as showers and thunderstorms. This leads to localised high totals with other areas seeing much less. Some places saw over twice their average rainfall for July. The Isle of Wight was very wet, as were parts of London which then experienced flooding. The rainfall map shows great contrasts with the brown, drier than average areas but the deep blues of heavy rain from the localised downpours. Many areas are shaded white to show average rainfall. The month was like a heatwave sandwich. Unsettled showery start, then the hot, sunny middle part with temperatures widely in the high 20sC and low 30sC. Then that faded and the showery weather returned with scattered thundery showers.
Holidaymakers were stunned by the high temperatures and ongoing sunshine as more families started their summer holidays. However, campers in Cornwall had a July shocker when Storm Evert arrived during the night of Thursday 29th. This wild low pressure was named by the UK Met Office alongside an amber wind warning as heavy rain and gales hit southern Britain towards the end of the month.
July 2021 will be remembered for the summer heat but the thunderstorms and heavy showers did cause disruption and flooding with a handful of funnel clouds causing some extra excitement,
Europe review by Copernicus of July 2021 with global temperature data. "Second warmest July on record for Europe. Third warmest July on record globally."