If you like hot weather then make the most of it this week because a "thundery breakdown" is being forecast for a weekend washout with temperatures dropping by as much as 10 degrees in 24 hours. Forecasters are predicting that Friday will be the hottest day of the year so far when temperatures could reach as much as 33°C as a mass of warm air heads towards the UK.
But it is not set to last very long as it is forecast to turn "cooler and fresher" over the weekend with the risk of heavy rain and thundery showers. The Met Office says that it will become increasingly warm in the south from Wednesday as high pressure builds. This will bring settled conditions allowing temperatures to build day-on-day and for it to become warm, or even hot, for a time by Friday.
Welsh forecaster Derek Brockway said this Friday it is predicted to be 30°C in Usk and 26°C in Machynlleth, but has warned it is not going to last long. The highest temperature on record in Wales was in June was 33.7°C in Machynlleth in 2000. The previous highest was 33.5°C in Usk in June 1976.
Temperatures are expected to be very high on Friday too, but Saturday looks very different with heavy rain in places and feeling a lot cooler. It comes as The Met Office and the UK Health Security Agency (UKHSA) issued a level 2 heat-health alert for a large part of southern and central England, with a level 1 alert in place for northern England, on Wednesday.
This is how the weather looks set to change between 1pm on Friday and 1pm on Saturday:
This is how the temperature looks set to change between 1pm on Friday and 1pm on Saturday:
The current Met Office Welsh forecast for the end of the week says: "Very warm or hot on Friday with plenty of sunshine. Perhaps the odd heavy shower later. Fresher for the weekend, with the potential for some heavy rain in places."
Mr Brockway said: "Friday will be the hottest day of the year so far and humid. But it's not set to last! Turning cooler and fresher over the weekend. Details are uncertain at this stage but there is a risk of rain heavy and potentially thundery."
The Met Office long-range forecast for next week says that Sunday is "likely to bring showery rain across the south with the chance of this becoming heavy or thundery at times."
For the rest of the week it says that temperatures will be close to normal for the time of year as a cooler, westerly wind will "bring showers for most".
On Wednesday, Parts of the UK will also be warmer than Greek Islands Santorini, Mykonos and Zakynthos – as well as Los Angeles and parts of Barbados. Greg Dewhurst, a Met Office forecaster, told the PA news agency: “The vast majority of England and Wales will see a lovely day on Wednesday, though slightly different in Northern Ireland and Scotland, which will see cloud and showers.
“It will be very warm in the South East in particular, with the temperature hitting a high of 28C, which would make it the warmest day of the year so far. This will then be surpassed on Thursday, with the mercury rising again to around 29C before reaching 33C and even 34C on Friday. So it’s going to be very warm as we move into the later part of the week.”