UK weather: Parts of UK officially in heatwave

Dog walkers walk past horses sheltering under trees on Basingstoke Common, Hampshire

Many parts of the UK are officially experiencing a heatwave as temperatures continue to climb to 30C.

The hot weather may have arrived at the weekend, but a heatwave is only being recognised now as areas in the UK have seen highs of at least 25C for more than three consecutive days.

A heat-health alert has been extended until next week as 30.7C was recorded in Porthmadog, Wales, on Tuesday.

The Met Office warned the humid air will bring thunder until this evening.

The forecaster has issued yellow weather warnings for thunderstorms in northern Scotland and western parts of Northern Ireland until 21:00 BST on Tuesday evening, with more rain and thunder possible later in the week.

Heavy rainfall resulted in flooding in the Golders Green area of North West London on Monday, as cars struggled to drive through waterlogged streets.

The Met Office defines a heatwave as three consecutive days with daily maximum temperatures meeting or exceeding the heatwave temperature threshold.

However, the threshold varies across the country, from 25C in Northern Ireland, Scotland, Wales, the North and South West of England, to 28C in parts of South East England.

Heatwaves are becoming more likely and more extreme because of human-induced climate change. The world has already warmed by about 1.2C since the industrial era began, and temperatures will keep rising unless governments around the world make steep cuts to emissions.

England's highest temperature of the year so far was at Chertsey Water Works in Surrey on Saturday after highs of 32.2C were recorded.

Bridgefoot in Cumbria has so far seen Tuesday's highest temperature in England, at 30.1C.

Northern Ireland started experiencing a heatwave on Tuesday too after temperatures climbed to 27C at Magilligan in County Derry and 28C in Armagh.

Highs of 30.7C in Porthmadog meant Wales also had its hottest day of the year so far on Tuesday.

Meanwhile, Scotland saw its hottest day of the year on Monday after temperatures reached 30.7C in Threave in Dumfries and Galloway.

Met Office spokesman Stephen Dixon said the rest of the week will be hotter than average for the time of year, but that the extreme heat may come down slightly, meaning that heatwave criteria may not last much longer.

"The heat is set to drop slightly in coming days. London might not meet heatwave criteria, for example, but there's a good deal of dry, fine, sunny weather to be had this week with temperatures remaining well above average," he said.

Last week's high temperatures led to the UK's Health Security Agency and the Met Office to issue an amber heat-health alert.

But all regions of England have now been placed under a yellow alert until 09:00 on Monday by the UK Health Security Agency, which means the hot weather is likely to affect vulnerable groups.

There are concerns about healthcare services becoming overwhelmed during this period, as well as an increase in the risk to health of people aged over-65 and those with pre-existing health issues, including respiratory and cardiovascular diseases.

In order to keep cool during the hot weather, people should ensure they drink plenty of water, wear loose-fitting clothes, stay in the shade as much as possible and use fans, ice and cool showers to reduce their body temperature.

Dogs and other pets can also be kept cool and safe by being kept out of the sunshine and not left in a hot car even for a short amount of time, along with being given lots of fresh water.