A heatwave arriving in London from Tuesday (July 28) to Thursday (July 30) is expected to be hotter than initially forecast, with temperatures peaking at 33C on Wednesday, according to the Met Office. The hot spell follows a July that has been 3C above average across the UK, with southern England receiving just 1% of its average rainfall.
Temperature Details and Timing
Temperatures will rise from 29C on Tuesday to a high of 33C on Wednesday, then fall to 28C on Thursday. The peak of 33C is expected between 4pm and 6pm on Wednesday, one degree higher than the 32C originally forecast last week. WX Charts also shows 32C at 6pm on Wednesday, often considered the most uncomfortable time for heat.
Long-Range Forecast and Climate Context
The Met Office's long-range forecast from August 10 to 24 suggests further heatwaves are possible, especially in the south. The forecast states: "Temperatures will probably be above normal and some spells of hot weather and heatwaves are possible, especially in the south." In London, a heatwave is defined as three consecutive days of 28C or higher.
Senior Met Office meteorologist Marco Petagna noted that UK heatwave thresholds may need adjustment due to the warming climate. "Going forward they’ll need to be adjusted to take into account… current climate, otherwise we’re going to more frequently go into heatwaves. It’s a moveable thing, really, as we go through a warming world," he said. Thresholds for some counties were raised by a degree four or five years ago.
Health Alerts and Impacts
A yellow heat alert has been issued from 9am Tuesday to 9am Friday for the East and West Midlands, south-east, south-west, and east of England, as well as Yorkshire and the Humber. The UK Health Security Agency warned of possible "significant impacts" on health and social care services, including increased deaths among the elderly or people with health conditions and a rise in drownings.
July Weather Statistics
Provisional Met Office data shows July has been 3C above average across the UK, potentially ranking among the hottest three or four Julys on record, according to meteorologist Mr. Stroud. Southern England has seen only 1% of its average July rainfall, England 5%, and the UK as a whole 20%.
Daily Forecast
Monday (July 27) will be dry with sunny spells and a high of 25C. Tuesday will be dry and increasingly very hot, reaching 29C. Wednesday will be sunny and hot, with temperatures in the low thirties, locally mid thirties. Thursday will start sunny but clouds may arrive in the afternoon, with significantly less warmth. Friday is expected to be mostly dry and warm with sunny spells and some cloud.
