According to Google/Gemini 1976 had 5 days at or over 35C and this is still so far the record

https://en.wikipedia.org/wiki/1976_British_Isles_heatwave 

It would be really useful to have a detailed dataset from (say) 1850 of all the data shown in Met Office "24 hour extremes in the UK"  available for analysis in one file

I don't think such a thing exists or even if the older data is even recorded, It would be a huge task to compile lit from the Met Office daily archives but it would answer a ton of the queries we see on here 

Yes AI said six for 2022, but I find AI quite poor when it comes to UK weather statistics.  Definitely some sort of database would be useful 

Unless I am missing something, I don't think the older Met Office summaries (pre 1990s) even include an overall max for each day, they just seem to show the maxima for the various stations, so it might not be very easy at all.

Roost Weather has a good feature where you can get the summary map with the top 10 temps for any given day right back to the 19th century (although records are obviously more sparse back then). Unfortunately though if you try and look at too many days at once it blocks your IP, presumably to prevent data scraping.

https://www.roostweather.com/ukobs/maxtemp_map.php 

From what I can see, 1976 and 2020 both had 5 35C+ days. 1990 and 2003 both had 3.

2022 only had two that I can see: July 18 and 19. August 13 came close with 34.9.

Beatable then. Especially if that GFS 12z comes off.

Very laborious and time consuming I am sure - presumably using the Met Offices Digital Archives which as you say vary in format over the whole period and  also the Met Office/CEDA Midas files which contain hundreds of daily Station histories over various time periods (when that station was active) going back 150 years or more.

I suppose someone must have done some of this work already in order to obtain lists such as the Torro Daily Extremes of UK maxima and minima going back to the 1800's at least for the hottest and coldest days of each year looking for candidate stations

Yes a briefer event than yesterday's 12Z but no less intense.

Maxima on the last four op runs runs have been 41, 32, 34 and now 41 again. This morning's ECM has several 30C+ days peaking at 36. You'd be brave to bet against another heatwave at the moment...

https://www.theweatheroutlook.com/twocommunity/Posts/t24642-Mid---late-June-2026-onwards-heatwave 

Yuck! I'm in the 38c zone and not really all that far from the 41c up by Norwich. Not something to look forward to.

It's been roughly a 1-in-3 chance I'd say for a couple of days now (in terms of a 30+ spell). Definitely worth taking notice of, and sod's law says it'll happen - definitely worth keeping an eye on.

I'd reckon that there's a good chance of a 43c or a 44c being modelled this summer. Or at least it definitely wouldn't surprise me.

One heatwave would be nice, we can't even manage 3 days over 25 C up here. The gap between England and Scotland's temperature's is increasing!

Cheers Brian. You beat me to it. 🙂🙂🙂🙂

https://x.com/peacockreports/status/2071239583300264000?s=46 

FWIW 1976 had exactly one month of consecutive days above 25C, from 21 June to 20 July inclusive. The longest such spell I could find was from July 18 to August 26 1995.