The Weather Outlook

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Brian Gaze
02 July 2026 17:14:46
GFS 12Z could be the hottest run of all time for the southern half of the UK. Utterly incredible.

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Brian Gaze

Berkhamsted

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Rob K
02 July 2026 17:15:33

So, longevity of heatwave. I looked up the longest number of consecutive days somewhere in the UK recorded 30C or more and of course the record remains June-July 1976 with 15 days, and the runner up seems to be August 2003 with 10 consecutive days.

The 1976 number is hard to beat even in a world that's 1.5 or 2C warmer, because it implies a very low level of day to day variability. 

In the GFS 06Z we got a definite 12 and probable 14 (maxes on the map this Sunday of 29 which usually means somewhere would see 30), with almost certainly at least a day or 2 more beyond the end of the run. So that would beat 1976 if it happened.

On the 12z so far we're up at 11 starting on Saturday running to 294hrs on the 14th, so that's a second run beating 2003 and threatening 1976. Both leave other events trailing in their wake.

Originally Posted by: TimS 

The data on Roost Weather, suggest that 1976 managed 18 consecutive days of 30C+, which is more than the oft-quoted stat (which I thought was 16?). 22 June to 9 July inclusive all had a max above 30C on there. 

Graph here: https://www.roostweather.com/ukobs/ukgraphs.php?type=yeardailyextreme&field=temp&year=1976&country=UK&__cf_chl_f_tk=HD5Cl_WxDc4ZhS0Jai.6cwb4bpjT2bIbtLPu4oqoYVs-1783012326-1.0.1.1-QEsRmMJG_wr.079TnCJQ2K3d7nJWJNTNq3Y0e6RqyXE 

Yateley, NE Hampshire, 73m asl

"But who wants to be foretold the weather? It is bad enough when it comes, without our having the misery of knowing about it beforehand." — Jerome K. Jerome

TimS
  • TimS
  • Advanced Member
02 July 2026 17:34:45

The data on Roost Weather, suggest that 1976 managed 18 consecutive days of 30C+, which is more than the oft-quoted stat (which I thought was 16?). 22 June to 9 July inclusive all had a max above 30C on there. 

Graph here: https://www.roostweather.com/ukobs/ukgraphs.php?type=yeardailyextreme&field=temp&year=1976&country=UK&__cf_chl_f_tk=HD5Cl_WxDc4ZhS0Jai.6cwb4bpjT2bIbtLPu4oqoYVs-1783012326-1.0.1.1-QEsRmMJG_wr.079TnCJQ2K3d7nJWJNTNq3Y0e6RqyXE 

Originally Posted by: Rob K 

That really is statistically freaky. When you consider the base level averages back then too.

I just lazily got my number from AI, so I’m sure your source is correct. 

Brockley, South East London 30m asl
Rob K
02 July 2026 17:57:28

That really is statistically freaky. When you consider the base level averages back then too.

I just lazily got my number from AI, so I’m sure your source is correct. 

Originally Posted by: TimS 

I knew 1976 had 15 days above 32C in a row. I didn't know the number for 30Cs was 18.. quite impressive really especially in those days as you say!

Yateley, NE Hampshire, 73m asl

"But who wants to be foretold the weather? It is bad enough when it comes, without our having the misery of knowing about it beforehand." — Jerome K. Jerome

Retron
02 July 2026 18:01:05
There was another effortless 27 here today (80F in old money, and I remember the fuss made about that in the 80s). The scary thing is that's with a NW'ly breeze, after a cloudy morning... it shows just how warm our surrounding area is, as frankly having a NW'ly bring 27C is just nuts - that used to take winds from a southerly quarter back in the day.

The MetO raw has 26/27/30/30/28/29 over the next few days. Nothing like we endured last week, but even so - the 91-20 average is 22, and even the coldest day will be 4C above. The 61-90 average was just 20... 

Leysdown, north Kent
+1
White Meadows
02 July 2026 18:05:49

So, longevity of heatwave. I looked up the longest number of consecutive days somewhere in the UK recorded 30C or more and of course the record remains June-July 1976 with 15 days, and the runner up seems to be August 2003 with 10 consecutive days.

The 1976 number is hard to beat even in a world that's 1.5 or 2C warmer, because it implies a very low level of day to day variability. 

In the GFS 06Z we got a definite 12 and probable 14 (maxes on the map this Sunday of 29 which usually means somewhere would see 30), with almost certainly at least a day or 2 more beyond the end of the run. So that would beat 1976 if it happened.

On the 12z so far we're up at 11 starting on Saturday running to 294hrs on the 14th, so that's a second run beating 2003 and threatening 1976. Both leave other events trailing in their wake.

Edit: yep it keeps going and ends the run with a cheeky 40

Originally Posted by: TimS 

I love posts like this. Important to remind ourselves that extremes are nothing new. 1976 remains an incredibly rare event and one which was prolonged perhaps beyond what our dynamic climatological conditions are capable of in the modern era in the UK. 

scillydave
02 July 2026 18:14:08

GFS 12Z could be the hottest run of all time for the southern half of the UK. Utterly incredible.

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Originally Posted by: Brian Gaze 

It's the heatwave to end all heatwaves. 

I've never seen anything like it before.

The Max temp is widespread above 32c in the Southern half of the UK for 2 weeks straight with a week long run of 36c and above culminating in widespread 40c at the end of the run. 

Thank god it's only one potential scenario out of many but it shows what's possible if everything aligns.

It would be a public health disaster in the Southern half of the UK

Currently living at roughly 65m asl North of Cowbridge in the Vale of Glamorgan.

Formerly of, Birdlip, highest village in the Cotswolds and snow heaven in winter; Hawkinge in Kent - roof of the South downs and Isles of Scilly, paradise in the UK.

scillydave
02 July 2026 18:18:10

I love posts like this. Important to remind ourselves that extremes are nothing new. 1976 remains an incredibly rare event and one which was prolonged perhaps beyond what our dynamic climatological conditions are capable of in the modern era in the UK. 

Originally Posted by: White Meadows 

Whilst 1976 was an incredibly rare event in it's day the chances of seeing similar heat now are much greater now.

What I fear is an incredibly rare 1976 event but in today's climate. The 12z GFS gives an example of this and would leave poor old 1976 looking like welcome relief!

Currently living at roughly 65m asl North of Cowbridge in the Vale of Glamorgan.

Formerly of, Birdlip, highest village in the Cotswolds and snow heaven in winter; Hawkinge in Kent - roof of the South downs and Isles of Scilly, paradise in the UK.

Retron
02 July 2026 18:19:35

The big 50c in France!!!

https://www.wetterzentrale.de/en/topkarten.php?map=16&model=gfs&var=17&run=12&time=363&lid=OP&h=0&mv=0&tr=3#mapref 

Originally Posted by: Ally Pally Snowman 

With a dewpoint of 4 - i.e. 5% RH - that would be utterly devastating. 

Leysdown, north Kent
+1
scillydave
02 July 2026 18:22:44

The big 50c in France!!!

https://www.wetterzentrale.de/en/topkarten.php?map=16&model=gfs&var=17&run=12&time=363&lid=OP&h=0&mv=0&tr=3#mapref 

Originally Posted by: Ally Pally Snowman 

I genuinely never thought I'd see that get modelled. That's truly extraordinary. 

2026 looks to be the year sh*t got real.

Currently living at roughly 65m asl North of Cowbridge in the Vale of Glamorgan.

Formerly of, Birdlip, highest village in the Cotswolds and snow heaven in winter; Hawkinge in Kent - roof of the South downs and Isles of Scilly, paradise in the UK.

+2
Ally Pally Snowman
02 July 2026 18:43:37

With a dewpoint of 4 - i.e. 5% RH - that would be utterly devastating. 

Originally Posted by: Retron 

Yikes!

Bishop's Stortford 85m ASL.
Col
  • Col
  • Advanced Member
02 July 2026 18:59:58

The big 50c in France!!!

https://www.wetterzentrale.de/en/topkarten.php?map=16&model=gfs&var=17&run=12&time=363&lid=OP&h=0&mv=0&tr=3#mapref 

Originally Posted by: Ally Pally Snowman 

The European record of 48.8C must surely be broken pretty soon, perhaps even getting the first European country into the '50C club'.

Col

Bolton, Lancashire

160m asl

Snow videos:

http://www.youtube.com/channel/UC3QvmL4UWBmHFMKWiwYm_gg

+1
saxtemp
02 July 2026 19:14:05
This would have been more appropriate for the June thread, but that's gone and might apply here anyway.

Has there ever been a year before that has had 35c twice, in 2 seperate distinct heatwaves? The way we are going, we could be looking at 3, but as far as I'm aware it's never happened twice before.

Rob K
02 July 2026 20:15:13

This would have been more appropriate for the June thread, but that's gone and might apply here anyway.

Has there ever been a year before that has had 35c twice, in 2 seperate distinct heatwaves? The way we are going, we could be looking at 3, but as far as I'm aware it's never happened twice before.

Originally Posted by: saxtemp 

2020 sort of counts, in that it had two 35C+ spells separated by a week. 37.8C on July 31 and then five days with temps in the 20s, before the main heatwave August 7 to 12 which had four more 35C+ days.

Yateley, NE Hampshire, 73m asl

"But who wants to be foretold the weather? It is bad enough when it comes, without our having the misery of knowing about it beforehand." — Jerome K. Jerome

Crepuscular Ray
02 July 2026 20:19:08

GFS 12Z could be the hottest run of all time for the southern half of the UK. Utterly incredible.

UserPostedImage

There's even a couple of 30 C's in the Central Belt on that one!

Originally Posted by: Brian Gaze 

Jerry

Edinburgh, in the frost hollow below Blackford Hill

Hungry Tiger
02 July 2026 21:39:22

The big 50c in France!!!

https://www.wetterzentrale.de/en/topkarten.php?map=16&model=gfs&var=17&run=12&time=363&lid=OP&h=0&mv=0&tr=3#mapref 

Originally Posted by: Ally Pally Snowman 

🙁🙁🙁🙁🙁

Gavin S. FRmetS.

TWO Moderator.

Contact the TWO team - [email protected]

South Cambridgeshire. 93 metres or 302.25 feet ASL.



westv
03 July 2026 08:28:50

The big 50c in France!!!

https://www.wetterzentrale.de/en/topkarten.php?map=16&model=gfs&var=17&run=12&time=363&lid=OP&h=0&mv=0&tr=3#mapref 

Originally Posted by: Ally Pally Snowman 

Where is the 50c? 

Big heat in May

Summer will be spray.

Ally Pally Snowman
03 July 2026 08:33:31

Where is the 50c? 

Originally Posted by: westv 

In the SW 

Bishop's Stortford 85m ASL.
westv
03 July 2026 08:37:11

In the SW 

Originally Posted by: Ally Pally Snowman 

Oh yes, just found it.

Big heat in May

Summer will be spray.

+1
Jiries
03 July 2026 09:11:53
I notice too much clouds around and wondering if this coming HP is a dirty HP or not? Supposed to be 25C today and sunny from today onward.
Matty H
03 July 2026 10:21:28

I notice too much clouds around and wondering if this coming HP is a dirty HP or not? Supposed to be 25C today and sunny from today onward.

Originally Posted by: Jiries 

Illegal clouds at that

Yate, Nr Bristol

TBFTEIARBSC

TimS
  • TimS
  • Advanced Member
03 July 2026 11:39:27
Another 15 days straight of 30C+ on the GFS 06z, and it’s at the moderately “cool” end of ensemble members.
Brockley, South East London 30m asl
The Beast from the East
03 July 2026 12:25:09

Another 15 days straight of 30C+ on the GFS 06z, and it’s at the moderately “cool” end of ensemble members.

Originally Posted by: TimS 

As you mentioned yesterday, this looks like 1995 on speed.  When we were 18, those same synoptics gave us uppers 20s. Now they give us 30s. 

Purley, Surrey, 70m ASL

"We have some alternative facts for you"

Kelly-Ann Conway - former special adviser to the President

Jiries
03 July 2026 14:38:55

As you mentioned yesterday, this looks like 1995 on speed.  When we were 18, those same synoptics gave us uppers 20s. Now they give us 30s. 

Originally Posted by: The Beast from the East 

I wonder if this month will do 1983 redux as well, as both 83 and 1995 had long straight settled warm to hot periods.  

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