The UK has begun to sizzle in a “relatively long spell” of hot days and “sticky” nights, as a heatwave begins for much of the country, the Met Office has said.
It reached 28.5C (83F) in St James’ Park, London, on Friday, which made the capital hotter than Los Angeles and Santorini.
Temperatures soared for much of the country, marking the first day of a heatwave for many which will continue into next week and potentially beyond.
Meteorologist Annie Shuttleworth said: “We’re at the start of a potentially relatively long spell of warm weather for much of the UK away from the far North West where it’s likely to be a bit cooler and cloudier.”
She added: “We’re looking at highs of about 31 degrees on Monday and Tuesday, we could see the temperatures come up to 32 degrees across the South East, so London extending up towards Cambridgeshire, that kind of area, is where the temperatures are expected to be highest, so they’ll be in the high 20s and possibly low 30s through quite a stretch of southern and central England and Wales.”
The Met Office’s definition of a heatwave is when a location records a period of at least three consecutive days with daily maximum temperatures reaching or exceeding the heatwave temperature threshold, which varies by UK county.
The Met Office expects many UK counties in the South West, including Devon, Dorset and parts of Wiltshire, to have marked the first day of a heatwave, with much of the rest of the country to follow suit from Sunday.
Ms Shuttleworth added: “So for some areas, namely parts of the South West, this is probably the start of their heatwave, but for the more widespread heatwave threshold temperatures to be met it’s likely to be from Sunday, so Sunday, Monday, Tuesday.”
The hottest day of the year so far was during the last heatwave on June 17, less than three weeks ago, when a temperature of 32.7C (90F) was reached.
Ms Shuttleworth added that temperatures will “come close” to this year’s high in London and the South East at the start of next week.
Parts of Scotland and Northern Ireland will also be seeing balmy temperatures, as across Aberdeenshire and Fife temperatures could be close to 27 or 28C, with 25C (77F) expected across Northern Ireland.
“In the sunshine, it’s going to feel very warm so it’s not advisable to spend prolonged time in the sunshine between peak heat hours of the day and to drink plenty of water,” the meteorologist warned.
The hot summer days are to bring with them hot and “sticky” nights, and Britons are urged to “keep the curtains closed during the day, especially if you’ve got a south-facing bedroom” and “keep ventilation going around your house through the day”.
The warm weather looks to be set in for some time to come, according to Met Office forecasting, with a chance that the UK could see one of the longest heatwaves ever.
Ms Shuttleworth said: “If we see over nine days of temperatures staying above 28 degrees then it would be the longest since 2018.”
She warned there was a lot of uncertainty around what temperatures will be seen after Thursday, but it is nonetheless likely that it will remain warmer than average for the month.
The average temperature for July is around 20C.