'Muggier' heatwave could top 34C in next few days as extreme heat warning issued

An extreme heat warning is in force for early next week as a high-humidity heatwave builds to a peak that could see temperatures top 34C (93F).

The Met Office says the low-30s are likely in southern England on Sunday, before the heat is expected to "expand and intensify" on Monday and Tuesday.

Humidity is set to be higher than last month's heatwave and the "tropical night" threshold - where temperatures don't fall below 20C - will be met in some areas.

The Met Office amber 'extreme' heat warning for Monday and Tuesday covers most of the South East, stretching to Norfolk, as well as parts of South Wales.

The forecaster says there's a 40% chance of beating June's highest-ever temperature of 35.6C (96F), set in 1957 and 1976.

It will also be hot further north at the start of the week, with 29C forecast for Manchester, 27C in Newcastle, 25C for Glasgow, 24C in Belfast.

"Temperatures have topped 30C in places this afternoon but the real heat has yet to reach us," says Sky News weather presenter Jo Wheeler.

After a slight cooling on Saturday, she says high pressure will "tap into the fierce heatwave over the near continent resulting in temperatures climbing day on day".

High humidity will make things "quite uncomfortable", Wheeler adds.

It's a message echoed by Met Office forecaster Honor Criswick, who says the upcoming heatwave will bring humidity "quite a bit higher" than the last one.

"It's just going to make it feel that bit muggier and that bit more humid during the day and overnight as well," says Criswick.

The Met Office alert runs parallel with one from the UK Health Security Agency warning people to look out for the elderly and those with underlying health conditions.

See the weather forecast where you are

Travellers heading to Europe for an early summer break could also be hit by unexpectedly high temperatures.

More than 50 areas of France are on heatwave alert, with interior minister Laurent Nunez warning of 40C (104F) in the day and and a sweltering 30C at night in some parts from Sunday.

Meteo-France - the French Met Office - describes the upcoming surge as "widespread, prolonged and intense

The water safety message is also being repeated after last month's UK heatwave - which set a new May record of 35.1C - saw at least 15 people die, including nine children.

Cold water shock - which can induce panic and rapid breathing - is still a possibility as sea, lake and river temperatures remain surprisingly cold.

People entering the water should go in slowly and gradually and swim in a lifeguarded area if possible, the RNLI advise.

Explainer: What is cold water shock?

"If you find yourself struggling in the water, remember to Float to Live: tilt your head back so your ears are submerged, relax and control your breathing," the RNLI's Samantha Hughes said.

"You may need to gently use your hands to help you stay afloat, and it's ok if your legs sink-everyone floats differently."

(c) Sky News 2026: 'Muggier' heatwave could top 34C in next few days as extreme heat warning issued