Heatwave Declaration Imminent as UK Experiences Unseasonal May Heat
A heatwave is anticipated to be officially declared for parts of the UK on Sunday amid a period of unusually high temperatures for May. On Saturday, a temperature of 30.5°C was recorded at Frittenden in Kent, marking the highest temperature of the year so far. These soaring temperatures may result in new national May temperature records being set on the upcoming bank holiday Monday.
The tourism and hospitality sectors are welcoming the timely hot and sunny weather; however, the extended duration of the heatwave is expected to have health implications for some individuals. Amber heat-health alerts remain active for regions in the Midlands and eastern England until at least Wednesday.
When Does Hot Weather Constitute a Heatwave?
The classification of a heatwave depends on regional climate norms. The Met Office defines heatwave temperature thresholds based on local averages. In Scotland, Northern Ireland, much of Wales, and northern England, the threshold is 25°C. For many other parts of England and south-east Wales, it ranges between 26°C and 27°C. In London, the home counties, and Cambridgeshire, the threshold is set at 28°C.
These temperature thresholds must be met or exceeded for at least three consecutive days to qualify as a heatwave. It is likely that many areas will be officially classified as experiencing a heatwave once Sunday's temperatures are confirmed. For some regions, this heatwave may become prolonged.
Temperature Records May Be Surpassed
Saturday marked the UK's first 30°C day of the year and the earliest occurrence of such a temperature since 1952. With temperatures expected to rise further across England and Wales on bank holiday Monday, there is an increasing likelihood that a new all-time UK May temperature record will be established.
The current highest May temperature is 32.8°C, recorded on the Late Spring Bank Holiday Monday in 1944 at Tunbridge Wells, Horsham, and Central London. Forecasts indicate the possibility of temperatures exceeding 33°C in parts of south-east England.
Additionally, the night-time May temperature record could be broken if any location remains above 18.9°C, the record set in Folkestone on the night of 30-31 May 1947.
Heat is expected to intensify across many areas during this bank holiday weekend. Forecasts suggest that some parts of England and Wales may remain above heatwave criteria for most of the week. While 30°C days in May are relatively rare in the UK, it is conceivable that four or five such days could be recorded this week alone.
Climate change is believed to have contributed to the frequency of such hot spells. According to the Met Office's State of the UK Climate report, the number of days with temperatures above 28°C in the UK has more than doubled, and days exceeding 30°C have more than trebled in the most recent decade compared to the 1961-1990 average.
Heat Distribution Varies Across the UK
Not all parts of the UK will experience sunshine and heat this weekend. Some areas of north-west Scotland are expected to remain fairly cloudy at times, with occasional rain and temperatures in the lower teens Celsius. Other regions of Scotland and Northern Ireland will experience pleasant warmth rather than intense heat, with temperatures gradually increasing over the coming days. The warmth in these areas may peak around Wednesday and Thursday, reaching mid-20s Celsius.
Coastal regions may experience cooler conditions due to sea breezes from the cooler sea. Regardless of temperature variations, UV levels are expected to be high across the UK.
Public Engagement
Authorities encourage the public to share how the hot weather is affecting them.
