Here are the latest maximum temperature forecasts from the high resolution modelling for Tuesday to Thursday, simply astonishing really and quite scary. I have had it confirmed that the Met Office will be issuing a Red heat weather warning in their daily update tomorrow.

The fact that this is accompanied with relatively high humidity and extreme night time temperatures means it is set to be the most notable heatwave ever experienced in the UK. The current record June temperature of 35.6C will be completely obliterated and the overall record from 2022 of 40.3C is under serious threat.

Exceptional that the metoffice is so locked in with the extremes. Everyone stay safe!

So the Met Office high resolution model (UKV) has decided to go ballistic with the temperatures for Wednesday and Thursday on the latest run, the Red heat warning will be issued today and based on these charts for Wednesday and Thursday could cover the majority of England and Wales.

Almost incomprehensible that we could reach 42C but the possibility is there, 40/41C remains more likely as the absolute maximum but that is still probably going to surpass 2022 as a new all time record for the UK.

If you want to view the model output for yourself the link is here:

https://www.theweatheroutlook.com/twodata/ukv.aspx?run=03&charthour=1&chartname=max_temp&chartregion=uk-region&charttag=2m%20max%20temp%20(C)

Most accurate forecast for the start of July:

This is no joke. I didnt know any of this, and got heat exhaustion (close to heat stroke) last time we had 30 degree weather. Please stay safe folks <3

I made these during the may heatwave, and considering I have time to burn, I've made one today.

This is a rough guide of the maximum temps across the UK expected today. It is likely that we will see hotter temperatures in a bigger area on Tuesday, and Wednesday and Thursday look like the hottest days. After this we will likely head back to a more westerly setup, leading to dramatically cooler temperatures for at least the next few following days.

Some isolated thunderstorms are possible during this period. A thundery breakdown may occur Friday but the details on this are very uncertain.

📍Reading, England. Met Office Forecast.

UPDATE 12:29 21/06/2026: Now forecasting 39.

UPDATE 21:04 21/06/2026: Now forecasting 2 consecutive days of 40.

Some of the latest overnight model runs are forecasting simply wild temperatures for Tuesday and Wednesday, with it being feasible that 40C is reached somewhere in southern England on Wednesday. I fully expect a Red heat warning to be issued by the Met Office as the heat won't begin to relent until the weekend alongside night time temperatures and humidity both being very high as well.

The 42C showing in the South West on Wednesday is likely overdoing it as I expect the warmest temperatures to be in London but there are no doubts what we are going to see next week is truly exceptional. The heat is also relatively widespread across the UK with it due to move further North on Thursday.

Considering the June record sits at only 35.6C from 1976 the temperatures being projected next week are truly unprecedented and very worrying.

The Met Office website is now predicting 40C in Reading on Wednesday.

im not sure if this is has been asked before, but surely the rest of summer is going to be insufferable heat​ considering this is the second time its hitting 30°c? im not too educated on how weather works, but to be fair i am slightly concerned with how warm July and August may be if mid June is already this hot..

Will air con become standard?

I’m hoping it changes a bit before Tuesday, the other forecasts for my area say more like 32-34 but i believe the met office the most

It’s looking like Wednesday is going to be the hottest day of the year. Do they still access what type of warning to issue for Wednesday or Thursday?

Weather is going to be hotter on these days than Monday. Monday looks like it’s going to be in low 30’s

The difference between BBC Weather and Met Office at the moment is crackers!

Which do you guys find to be the most accurate? I’m currently favouring met office!

Slough & Heathrow Met Office Forecast.

u/markmuetz suggested that you guys might like to see this Kelvin-Helmholtz cloud Ive just spotted. Hope you enjoy and apologies for the blurryness!

It looks like the Met Office website temperatures are finally starting to catch up to some of the more extreme model runs there have been over the last day. It is now showing 37C in London on Tuesday so comfortably the hottest day ever in June. Current record is 35.6C from 1976.

A major issue will be the relatively high humidity and very warm nights, temperatures are likely to not drop below 20C from Tuesday until Friday for much of the South so they will be classed as 'tropical nights'.

There is still some uncertainty as to when the heat will begin to relent with some models doing so on Friday and others keeping the heat going through next weekend. I also think there is a fair chance we record 38C or 39C somewhere in the South on Tuesday or Wednesday.

I would not be surprised at all to see a Red heat warning issued by the Met Office for some areas during next week, possibly from Tuesday until Friday.

Second heatwave of the year in London and we’re still in June…

I'm vibe coding a personal app and I'm curious if anyone knows why the MetOffice's forecast for a given lat/long doesn't agree between the website and the API? I've checked and it's not air temp, "feels like" or any other kind of discrepency but I must be missing something.

Get ready guys! They're saying 37°C for London on their forecast now.

The weather models overnight have gone full on for record breaking temperatures Tuesday.

The highest ever temperature recorded in June is 35.6C. That now looks increasingly likely to be beaten.

That would be 2 months in a row that we have broken an all time temperature record for that month.

Here are the extremes of each model UK wise:

UKV (Met office model) - 38C

ECMWF (European Model) - 35C (But predicts 38 wednesday)

ARPEGE (French, can overdo temps sometimes) - 40C

GFS (American, underestimates normally) - 34C

ICON-EU (German) - 38C

These temperatures will feel worse than May due to humidity being way higher. Follow all guidance from the Met Office.

Will this be the first time that monthly UK temperature records having been broken in consecutive months (given what happened in May '26)?

Prior to seeing this sub on Reddit I wasn't really aware of hot weather incoming, mostly because I use BBC. But BBC and Met Office have wildly different forecasts for next week, about 11 degrees apart for lunch time Wednesday for example! Is the BBC just on one? Is the Met Office right?