Large parts of the UK are officially experiencing a heatwave, the Met Office has confirmed.
Temperatures have soared across the country since the weekend, with many areas passing the heatwave threshold in the warm weather.
A heatwave is experienced when a location records a period of three consecutive days of high temperatures.
Saturday was the hottest day of the year so far, with 32.2C recorded at Chertsey in Surrey.
Read more: How hot is too hot in the UK's heatwave?
Temperatures have cooled slightly this week, but have largely remained in the high 20s.
Almost all of the UK was battered by thunderstorms and heavy rainfall on Monday.
Watch: Week of sunshine predicted across the UK
However, sunny and dry conditions are expected in most areas for the rest of the week, meaning even more locations could reach the heatwave threshold in the coming days.
On Tuesday, the Met Office said 35 different counties across the UK were experiencing a heatwave, having had high temperatures on Saturday, Sunday and Monday.
These include 27 counties in England, five areas in Scotland, two in Wales and one in Northern Ireland.
These are the areas and counties that are experiencing a heatwave:
Ross and Cromarty
Met Office spokesman Grahame Madge told Yahoo News UK: “Yesterday was the first day of official heatwave conditions in the UK during 2023.
"Conditions are likely to be widely met again this week. But with a three-day or more threshold, heatwave extent will shrink with cooler conditions.”
What's the threshold for a heatwave in the UK?
According to the Met Office, a heatwave is "an extended period of hot weather relative to the expected conditions of the area at that time of year, which may be accompanied by high humidity".
The Met Office said the UK heatwave threshold is when when a location records a "period of at least three consecutive days" with daily maximum temperatures meeting or exceeding the heatwave temperature threshold.
Watch: Weather: Parts of the UK experiencing heatwave, Met Office says
This threshold varies by UK county, from 25C in Northern Ireland, Scotland, Wales and the North and South West of England, to 27C and 28C in the South East of England.
Is there a link between heatwaves and climate change?
In a study carried out in 2018, the Met Office said human-induced climate change made record-breaking high temperatures 30 times more likely than they would be naturally.
Met Office scientist Dr Nikolaos Christidis said in December 2018: “Our models show that there is now about a 12% chance of summer average temperatures being as high as the UK experienced in summer 2018. This compares with a less than half per cent chance we’d expect in a natural climate.”
The highest ever UK temperature of 40.3C was recorded on 19 July last year at Coningsby in Lincolnshire.