How long will the heat last and what about Glastonbury weather?
Why so warm?
After a cooler than average start to June, this week sees the first burst of summer heat arrive on our shores. Having ditched the chilly northerly wind from the Arctic, the UK will find itself bathed in tropical maritime air from the mid-Atlantic.
This will not only bring a rise in temperature, but also humidity – making it feel muggy by day and uncomfortable for sleeping at night. However, the level of warmth isn’t anything unusual for the time of year, it’s just been a long time coming.
How long will it last?
The heat will last longest across England and Wales, continuing until Thursday, before a cold front brings cooler air and a little rain. Before it cools down, temperatures are widely expected to reach the mid to high 20s, with a few locations possibly reaching 30C.
Most of Scotland and Northern Ireland will have had their warmest day of this week on Monday, reaching the low to mid 20s. That’s because cloudier skies and fresher air will start to drift in from Tuesday onwards, restricting temperatures to the high teens or low 20s Celsius instead.
Heat-health alert
You may have seen in the news that there’s a yellow heat-health alert for much of England. These are issued for the health and social care sectors, to highlight that heat and humidity may impact vulnerable parts of the population – the elderly, the young and those with pre-existing health conditions.
Heat-health alerts are not the same as extreme heat warnings, which are issued when extreme temperatures are expected to impact the wider population. Given that this week’s heat is typical for the time of year, no extreme heat warnings are going to be issued.
Not always sunny
Something else that’s worth highlighting is that despite rising temperatures, it’s not going to be sunny all the time. Across England and Wales, old weather fronts are drifting around beneath the area of high pressure. These contain some moisture, which when heated will lead to some cloud building up through the day. This will lead to a mix of clouds and sunshine, rather than clear blue sky.
As I mentioned earlier, Scotland and Northern Ireland will see a weather front arrive from Tuesday. This will bring cloudier skies and some showers or rain from time to time.
Glastonbury weather
Glastonbury festival gets underway later this week, and part of the experience will depend on the weather. If it pours with rain, it can turn into a mud fest. If it’s too hot and sunny, the lack of shade can cause people to suffer from heat-related illnesses.
When I presented my weather forecast there back in 2014, there were thunderstorms which caused the main stages to be closed for a while. The atmosphere was still brilliant though, and to this day is my favourite outside broadcast that I’ve ever done.
This year, the weather looks unlikely to cause any major problems. Aside from an isolated shower, Wednesday should be mostly dry, fine and humid, with a temperature around 26C. Thursday will turn cooler and fresher at 21C, with the possibility of some light rain moving through. Thereafter, it should remain fine and dry with temperatures in the low 20s. UV and grass pollen levels will be high or very high though, so don’t forget the sunscreen!