Parts of the UK will just miss out on an official heatwave despite temperatures remaining high, the Met Office has said.

To meet the definition of a heatwave, areas must see three consecutive days of high temperatures – ranging from around 25C to 28C – depending on location.

Although temperatures around the country are expected to stay in the twenties on Thursday, most places will not “tick the box” for a heatwave.

It comes as temperature records for the year were smashed on Wednesday, with the mercury climbing to almost 30C in some places.

Northolt in west London peaked at 28.3C on Wednesday afternoon, surpassing Tuesday’s record of 26.1C in Cardiff, and meaning the UK recorded its third successive warmest day of 2021.

Parts of Surrey and Kent also saw temperatures of between 27 and 28C, while the village of Hawarden in Flintshire reached 26.5C to become Wales’ own warmest day of the year.

Scotland also recorded its hottest days of 2021 with Achnagart reaching 25.4C, while the 23.3C in Ballywatticock, Northern Ireland, matched its previous warmest day of the year.

The warm weather has been a welcome break for people following a washout May, which brought heavy downpours and prolonged spells of rain for much of the UK.

But Steven Keates, meteorologist at the Met Office, said it was “unlikely” that heatwave criteria would be met.

“We define a heatwave depending on three consecutive days meeting certain temperature thresholds and it depends where you are in the UK – it ranges from about 25 to 28 degrees,” he said.

“My suspicion is that a handful of places will come close to meeting the thresholds but not many will tick the box for a heatwave.

“I think it’s going to be a bit of a near miss for most places.

“It’s been a lovely warm spell but if we’re using the strict criteria we use to measure it then I don’t think anywhere is going to quite get it this time.”

He added: “Nonetheless we’re going to see several very warm days up and down the country which will be welcome for a lot of people after what has been a pretty cool, damp, disappointing May.

Some areas in south-west England and south Wales, which had enjoyed sunny and warm weather in recent days, experienced some heavy showers during Wednesday afternoon.

Mr Keates said temperatures were expected to stay above 20C in most areas on Thursday with the highest, most “humid” temperatures being felt in the east, with up to 27C predicted in east Anglia.

He added: “weather-wise it will be a bit of a mess”

“The showery rain tomorrow morning will pivot a bit and push its way toward Scotland.

“Elsewhere across England and Wales it’ll be a bit cloudy and dull to begin with but we should see some sunny spells in the afternoon.

“It’ll be pleasantly warm for most of us but a bit humid in the east tomorrow.”

Mr Keates said that more heavy rain was expected late on Thursday and overnight on Friday.