Thursday 19th June 2025

Congratulations, it’s a heatwave! A few hot days to come, but becoming somewhat less hot from Sunday.

Thanks to Isabel for the photograph (and assuming that I might need more fair weather photographs).

So the general picture sees high pressure over the UK and just drifting slightly east, which allows some of the hotter air to move up from Spain – though unlikely it will break June records (might be a close call though).

The hotter air is actually arriving a day or so earlier than previously expected, and being shunted away a day or two earlier than expected because there is a bit more energy in the jetstream – the low pressure to the north of the Azores right now is going to be picked up as part of the circulation of the low pressure south of Greenland – and hence the heat isn’t quite going to get to the levels once thought possible.

Anyway, today is hot and sunny. Very little if any cloud and reaching around 30’C, maybe 31’C – easily the hottest day of the year so far. I wouldn’t rule out 32’C. Fairly clear skies overnight though some high cloud around, probably no lower than around 16’C so a fairly warm night.

Friday sees more in the way of high-level cloud so hazy sunshine is the theme, and a bit of a breeze too. But still hot, 29’C, maybe 30’C – I cannot totally rule out something a tad more. Mostly clear skies overnight, though a little cloud around, and a fairly warm night – probably no lower than 18’C.

Saturday starts fairly sunny. There will be some cloud at times as things start to break down from the west, and I cannot totally rule out a short heavy shower, but sunny spells will be the theme. Hot, though some uncertainty as to how hot. 30’C is the lower end of the possible range, 34’C is the upper end, I’d suggest 32’C more likely. The June record is 35.6’C – I’d say there is a 10% chance of this being breached, more likely in the Midlands area. Some cloud in the evening and a 30% chance of a shower, perhaps thundery – though they will probably be quite scattered (if they even develop). Likely a warm night – fresher air will arrive at some point, but don’t be surprised if it is still 25’C at midnight, and a notably uncomfortable night. Fresher air may arrive around midnight – but more likely not until around dawn.

By Sunday, low pressure is more in control, and high pressure has been shunted back into the continent.

Sunny spells and variable amounts of cloud will be the theme, around a 20% chance of a passing shower, though unlikely it would amount to much if you caught one. Still some residual warmth, 26’C should be achieved, maybe even a little more – though the westerly breeze will make it feel more comfortable. A weak weather front will cross overnight bringing some cloud, maybe some showers – and a fresher night – roughly down to around 12’C.

For Monday, plenty of sunny spells, some cloud around – it should be dry too. Warm, around 23’C in a westerly breeze. Probably clear skies and dry overnight, around 13’C.

Fairly low confidence for Tuesday, but suggestions of a weather front crossing which would suggest a cloudier day with maybe a bit of rain, and around 21’C or so.

Low confidence afterwards – I’m actually more confident for next weekend than I am for the Wednesday to Friday period before it. So for next weekend I think there is a good chance (never certain at this range) of it being hot and sunny once more.

It’s how we get there that is trickier (with apologies for those going to Glastonbury hoping for a bit of certainty!). I think the more likely outcome is a slow build up of warmth towards the weekend, with mostly sunny days.

But there’s certainly a fair chance instead of something more changeable, maybe some thundery showers or even a band of rain crossing, with Wednesday/Thursday being the more uncertain days.

That’ll do for now. Enjoy the heat if you can (I shall be enjoying my air conditioning, quite how I used to cope without I have no idea), next forecast might be Sunday morning, or Monday if not.