I've just run my E&W summer index up to the end of July to see how the summer so far compares historically. The answer is a bit meh.

As a quick recap, I use E&W mean temperature, precipitation and sunshine hours from 1971 to now, normalised so that each time series has an equal long term Std deviation i.e. the influence of variability in each measurement is equal.

June scores a creditable 140 (vs 1971-00 mean of 125), putting it 9th in the list out of 54; July scores only 161, in 11th place. That puts it behind many recent Julys including 2013 and 2014, 1999, 1990 (though interestingly, and contrary to received wisdom, not far off July 1995 and ahead of July 1975).

This is almost entirely down to disappointing sunshine hours. 212.7 in the month, an average of only 6.9 hours per day. Less sunshine than June. Jiries is, as so often, right on the money.  

The more interesting stats are for the last 12 months. Last Autumn was 9th highest, winter 3rd, spring 6th, and summer looks likely to be in the top 5 or 6 at least. The highest scoring calendar year by some way is 2003 with a score of 90, followed by 1989 then 2018. Record could be up for grabs this year through consistently good scores rather than any standout months.

Originally Posted by: TimS 

I use Kevin Bradshaw's "Manchester Summer Index" formula but feeding in the data for London (Heathrow) instead

I believe this also has normalised Stdev values as adjustments  for MaxT, Sun Hours and Rain Days the same as yours

The rain days and sun hours are then pro-rated up to 93 days from whatever day number of summer it is (today is day 82)

Only 1976 at 364 is ahead of 2022 (341) in this part of the world but 1995(336), 1911(335) and 2018(333) are close behind and could well overtake if the last 10 days of this month go with forecast

Originally Posted by: lanky 

This is almost entirely down to disappointing sunshine hours. 212.7 in the month, an average of only 6.9 hours per day. Less sunshine than June. Jiries is, as so often, right on the money.  

Originally Posted by: TimS 

Not that disappointing as the average for London is 192 hours though some sources put it as high as 219. 

https://www.currentresults.com/Weather/United-Kingdom/average-sunshine-july.php#a
https://weather-and-climate.com/average-monthly-hours-Sunshine,London,United-Kingdom

Jiries may well have felt let down after June but I think he was OTT claiming in some posts that the total was closer to 100 hours for this July.

Originally Posted by: DEW 

Indeed, I believe the phrase used was “well below 100” hours.

Originally Posted by: doctormog 

But Jiries is a national treasure who should be treated tenderly and with forebearing.

The E&W sunshine hours for July were OK compared to average, indeed a little above I think, but they are the main reason July wasn’t right up there with the top months. The temperature was respectable - 6th highest - and it was extremely dry, but the sun hours were mid ranking. 

Not sure what August sunshine will look like. We had about 6 days of almost unbroken clear sky across most of the country during the heatwave which will have set things up nicely, but a cloudier interlude since and a fairly cloudy run in to September by the look of things. 

July 2006 remains the champion of combined heat and sunshine. It’s easily the top scoring month on the summer index - both the hottest and the sunniest. Only July 2018 (and the famously snowy June 1975) comes close for sunshine.

Originally Posted by: TimS 

This tallies with what the regional series show long term in my summer index too - haven’t updated for 2022 yet but I have a time series showing SI of “SE and central South” vs “North West and N Wales” and there is a very marked trend. The SE is getting warmer (and sunnier and drier) more rapidly than the NW. Last summer was of course an exception to the rule. 

Originally Posted by: TimS 

The NW/SE trend was also what  I noticed when I mapped the Summer Index trend from 1961 to 2016 a few years ago

Originally Posted by: lanky 

Really marked differences, with some interesting sub-regional patterns. Some of this looks like an impact of more westerly flow - better scoring NE coast, Thames Estuary, worse scores in windward hill ranges and coasts - but the pattern appears completely reversed in Scotland North of the central belt (the Richardabdn effect).

The Thames Estuary pattern is really pronounced (the Retron effect). The odd pattern around the Wash likewise - hard to know why. 

Originally Posted by: TimS 

Originally Posted by: Rob K

{Out of curiosity in the rankings of the hot UK summers I have collected together the data where I can (the full daily data for 1976 for the entire summer seems impossible to find, so I have only got the 30C+ days there).

For info, listed as year, followed by days above 25C, 28C, 29C, 30C, 32C and 35C in the three summer months.

1976: ?, ?, ?, 17, 15, 5
1995: 61, 40, 31, 27, 12, 1
2018: 59, 33, 27, 24, 6, 2
2022: 38, 24, 17, 11, 5, 2 (up to 9 August).

1995 is still the daddy as far as I am concerned, with a whopping 27 days above 30C, and 40 above 28C. However when talking extreme heat duration (above 35C), 1976 is the champ for now.

After the coming week, I think 2022 is likely to take the "extreme heat" crown from 1976, but 1995 is still the overall summer to rule them all. Shame about the cruddy start to June though - 8 days in the first half of June 95 failed to even reach 20C!{

The fact this summer hit 40C in this country in my view puts this summer in a class of its own.

Originally Posted by: Hungry Tiger 

I think some of it has to do with huge sunshine hours changes in post-industrial areas

Originally Posted by: lanky 

We actually failed to get any 35C+ days from that recent hot spell, as the maxima were quite a lot lower than originally forecast (there was talk if 37 or even 38 at one stage!). So still only 2 for this year.

@APS: the last day not to reach 25C was August 5th. Before that you have to go back to July 27. So only one day in the last 26 has failed to reach 25C.

Originally Posted by: Rob K 

Just confirmed from the Met Office - a new high minimum temperature record from the July Heatwave. A staggering 26.8c!!
This comes from a late reporting station and supercedes the Kenley record set on the same day of 25.8c

Originally Posted by: scillydave