The UK has recorded its all-time highest May temperature as part of London reached 34.8C on Monday. That provisional figure, recorded in Kew Gardens, also surpassed the hottest bank holiday Monday on record – 33.3C on the August bank holiday in 2019.
Wales has also experienced its hottest May day, reaching 32.2C at Hawarden Airport in Flintshire.
“This heat would be exceptional in the UK even in mid-summer, let alone in May”, the Met Office said.
The mercury is expected to rise further on Tuesday, with forecasters warning of possible 35C heat in parts of England.
The UK recorded its warmest May night on Sunday, with highs of 19.4C in London.
This week’s weather means more than half of the monthly record highs – seven out of 12 – have been set since 2003, according to the Met Office.
These exceptionally high temperatures have been caused by “the influence of warmth building under an area of high pressure near the UK”, Met Office chief operational meteorologist Dan Suri said.
The average temperature for the end of May is 14-20C.
On Friday, the UK Health Security Agency issued its first amber-heat health alert of 2026, covering much of England, including the West Midlands, East Midlands, East of England, South East and London.
The North East, North West, South West, Yorkshire and Humber regions are under a yellow alert. Both alerts will remain in place until 17:00 BST Wednesday.
Scotland and Northern Ireland recorded their highest temperatures for 2026 so far on Monday – 25.5C in Charterhall and 25.8C at Derrylin in County Fermanagh respectively.
Around 500 properties in Sussex and Kent were left without water, or had intermittent supply due to “increased demand”, on Monday afternoon.
Apologising for the disruption, South East Water said it was working “as quickly and safely as possible” to resolve the issues.
Across the UK a number of bank holiday events were cancelled because of the extreme heat.
