The UK Health Security Agency has issued an amber heat health alert for large parts of southern and eastern England as the country braces for the fourth heatwave of the year, with temperatures forecast to reach 35C on Wednesday.
The alerts, in force from 09:00 BST on 29 July until 09:00 BST on 30 July, cover the East Midlands, East of England, London and the South East. Less severe yellow alerts have been issued for the same period across the South West, West Midlands and Yorkshire & The Humber.
“Amber heat health alerts issued as fourth heatwave peaks at 35C on Wednesday, with wildfire risk elevated across UK.”
The heat is being driven by a plume of intense air surging north from North Africa, which has already brought exceptionally high temperatures to parts of Iberia and France. Wednesday is expected to be the hottest day of the week, with the mercury climbing sharply in southern and eastern England and parts of the Midlands.
Met Office Deputy Chief Forecaster Gregory Wolverson said: “This is a short-lived spell of heat, but temperatures will climb quickly through the first half of the week, particularly in the southeast. By Wednesday, some areas could see temperatures in the mid-30Cs, and while the heat will not be widespread across the whole of the UK, it will be enough for parts of the southeast to likely meet official heatwave criteria by Thursday.”
The warmest counties are expected to include Berkshire, Surrey and Buckinghamshire. Monday’s peak was 28C at Heathrow Airport in west London.
The hot and dry conditions have already stoked wildfires. Firefighters battled a blaze in the Cairngorms for at least 10 days, forcing families to leave their properties. Across the UK, the wildfire risk “remains elevated” after more than 200 fires in the last fortnight, according to the Evening Standard. In France, hundreds of thousands of people have been evacuated as blazes put the country in its most difficult situation since the Second World War, President Emmanuel Macron said.
The lack of rainfall means dry ground and low soil moisture levels remain a concern. While rain and showers are forecast for Northern Ireland, Scotland and the far north of England, barely a millimetre is expected elsewhere.
Thursday will bring relief for most, with temperatures falling by around 5-8C compared to Wednesday’s peak. However, the South East will remain warm, with the mercury still forecast to reach 29C, matching the heatwave threshold. Humidity will ease, making sleeping more comfortable, but well-above-average temperatures in the mid- to high 20s Celsius will persist into the weekend.
For Scotland and Northern Ireland, temperatures will only reach about 20C at best, with southern parts of Scotland and most of Northern Ireland likely to see showers throughout Wednesday.
