The Met Office has issued an Amber Extreme heat warning with temperatures expected to build through the week.

The Extreme heat warning, which covers much of the southern half of England as well as parts of eastern Wales, will be in force from Thursday through until the end of Sunday with impacts possible to health, transport and infrastructure.

The forecaster said heat will build through the week, peaking on Friday and Saturday thanks to the influence of high pressure positioned over the UK. Temperatures are likely to rise into the low-to-mid 30s Celsius for those within the warning area. However, temperatures are not expected to be as extreme as those experienced in July when new national records were set.

Outside the warning area, heatwave criteria are still likely to be met for much of the UK, with temperatures widely into the high 20s Celsius with a chance of a few spots seeing temperatures into the low 30s. Scotland and Northern Ireland will also see temperatures into the high 20s and could reach official heatwave criteria by Friday.

Met Office Deputy Chief Meteorologist Dan Rudman said:

“Thanks to persistent high pressure over the UK, temperatures will be rising day-on-day through this week and an Extreme heat warning has been issued.

“Temperatures are expected to peak at 35C on Friday and Saturday, or even an isolated 36C on Saturday. Elsewhere will see temperatures widely into the high 20s and low 30s Celsius.

“Coupled with the high daytime temperatures there will be some warm nights, with temperatures expected not to drop below the low 20s Celsius for some areas in the south.”

The UK Health Security Agency has also issued a Level 3 Heat Health Alert, which is designed to help healthcare professional manage through periods of extreme weather. The Alert is in force from Tuesday through to Sunday, with the UKHSA advising people to look out for vulnerable people, including older people, young children and those with underlying health conditions.  

Little rain in the forecast

After the driest July in England since 1935, there is little in the way of rain in the forecast, with only the northwest of the UK likely to see any short-lived showers, with details still being determined later in the weekend and into early next week.

Dan Rudman continued:

“With high pressure dominant this week, any showers this week will be contained to the far northwest, and even here they will be short-lived in nature.