Hottest May day on record expert comment

Professor Andrew Charlton-Perez, professor of meteorology and head of the School of Mathematical, Physical and Computational Sciences at the University of Reading, said:

 

"To use a scientific term, the weather has been absolutely flipping roasting. It has been the hottest ever May day recorded in Reading. 

 

"The maximum temperature soared to 32.8 °C just before 2pm, equal to the previous hottest ever May day set anywhere in the UK before today. The previous Reading record was set on 29 May 1944, just a few days before D-Day, when 31.9°C was recorded.

 

"Days with temperatures over 30°C are quite rare, but they are getting much more common. In Reading, we have recorded the temperature on 42,785 days since 1908, and only 253 of those have gone above 30 degrees. 

 

"But it is getting much more common. We've seen days reaching above 30°C three times more frequently during the last 10 years than in the 100 years before that."

 

Regius Professor Hannah Cloke, Regius Professor of Meteorology and Climate Science at the University of Reading, said:

 

"Climate change has an impact on a whole range of weather patterns, but their influence on heatwaves is one of the most straightforward to trace. A hotter atmosphere is increasing the likelihood of UK heatwaves, bringing them earlier in the year and intensifying their peak temperatures.

 

"We are now increasingly seeing a seasonal shift, with heat emerging in late spring or early summer that you would not previously have expected to see until mid to late summer. Higher background temperatures provide a warming springboard from which typical high-pressure systems can more readily trigger heatwave conditions. 

 

"The hotter atmosphere acts as a heat reservoir, supplying extra energy that lifts peak temperatures. At the same time, there is some evidence that more persistent high-pressure blocking patterns can develop, allowing the famously changeable British weather to become stuck in one position for longer, enabling heat to build and linger."

 

Professor Ed Hawkins, professor of climate science, University of Reading, said:

 

"The heatwave of May 2026 stands in contrast to heatwaves we have felt in the past in the UK. The key shift is not simply higher peak temperatures, but longer periods of exposure.

 

"Past heatwaves have tended to develop later in the summer, been more limited in extent, and have been more marked as they were seen from a cooler climatic baseline. Today’s heat events are emerging earlier, intensifying faster, and occurring across a much warmer background climate.

 

"This means that the window for potentially dangerous heat is expanding. Conditions once considered exceptional are happening over and over, with sustained heat risk increasingly defining future British summers."