I was going to pop a comment into the heatwave thread but it seems to have lost itself a tad.

Today brings, at 22.9C max, the end of a 17 day run of maximum temperatures here of 24.0C and above. That might seem an arbitrary threshold- in some respects, I suppose any is; but I wondered how it compared to some of the more recent good spells.

Shame I don't know how to insert a table!

2018  June - July 17 consecutive days

2013 July 12 consecutive days (would've been 19 if it wasn't for a 22.1 spoiler on 11th)

2006 July  8 consecutive days (even with 23rd at 23.1 taken out, ie if it had been 0.9C warmer,  it would still have been just 14 days)

2006 June-July 5 consecutive days

2005 July 6 consecutive days

2003 August 12 consecutive days

2003 July 5 days (would only make 8 without the spoiler)

2001 July-Aug 2001 7 consecutive days

You will have your own series, and maybe you'd like to shift the threshold up or down. But as I really enjoy 24C days, I recognise that the current spell is exceptional and may have echoes in Aug 95 or July 83.

I tend to use 25C as a benchmark but taking your figure of 24C for consistency I have the following stats.

2006 was the big daddy but in many ways I would say 1995 comes second for prolonged heat. There were just four slightly cooler days in a 40 day spell of remarkable weather. Just 9.5mm of rain in that 40 days.

2018 24 Jun-9 Jul - 16 days (first time such an extended hot spell has started in June since I started recording data)

2013 12-27 July - 16 days

2006 11-30 July - 20 days

2003 2-15 Aug - 14 days

1997 7-21 Aug - 15 days

1995 23-Jul to 6 Aug - 15 days (this backloaded summer was exceptional - temperatures exceeded 25C for 36 out of 40 consecutive days)

1990 11-28 Jul - 18 days

1989 15-29 Jul - 15 days

No official stats, but I'd wager my trousers that MBY has seen the temp hit 24c for at least the last 40 days and counting - with zero ppn during that time. 

A remarkable spell.

40 consecutive barbecues - thats cheating!

Here are the official stats for Rostherne which is probably the closest non-coastal SYNOP station to your location. I make it 17 days.

http://www.ogimet.com/cgi-bin/gsynres?lang=en&ord=REV&ndays=30&ano=2018&mes=07&day=10&hora=18&ind=03351

Daily max temps locally have really come down in the last week, wavering between 19-23c generally, which is still a bit too much for me. More broadly, if it wasn't for the 24.9c recorded in Oak Park in the SE of the country on the 6th, that region would have reported its 17th consecutive day with temp of 25c or over (as of yesterday)

Something similar came up the other day in the June CET thread with respect to the record-breaking June temperature in 1846

I had a look at record breaking warm spells lasting 16 days or more as recorded by the daily CET record going back to 1772 for any month of the year not just summer

There were only 7 occasions when there were 16 or more consecutive days when the daily CET was 3.0C or more above the average CET for that month (1961-90 basis)

The rest of the post from a few days ago is here

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I had a look at the daily CET records to see if there was a clue as to what happened in 1846

There were no record breaking hot days and the highest CET Mean was on the 22nd June 1846 at 22.0C. This only ranks 16th= in the table of record daily CET Means for June

Where the record came from I think was just the sheer length of time the hot spell lasted and the fact it was completely contained inside one calendar month

The daily CET Mean had an anomaly value exceeding +3.0C (1961-90 basis) on 20 consecutive days from 3rd to 22nd June and during that period the average anomaly was +5.19

It is extremely rare to get that many consecutive days with a CET Mean at 3C or more above the average and in fact if you take a yardstick of 16 consecutive days instead of 20 it has still only happened 7 times since daily records were started in 1772 - and a number of these cross over month boundaries

FWIW the actual 7 are

13Jan - 3 Feb 1804 (21 days +4.42 av)

9 May - 25 May 1833 (17 days +5.32)

3 Jun - 22 Jun 1846 (20 days +5.19)

1 Sep - 16 Seo 1865 (16 days +4.40)

22 Jun - 9 Jul 1976 (19 days +6.89)

6 Aug -23 Aug 1997 (18 days +5.04)

15 Dec -30 Dec 2015 (16 days +5.83)

I know Rostherne, but those figures aren't representative of here. We've had zero ppn during that entire dataset, too

In any case there is no chance St Helens has had 40 or more consecutive days over 24C. Literally nowhere in the UK has achieved that.

Indeed not. 40 days takes us back to the beginning of June and in the middle of that month I recorded quite a few days in the high teens, nowhere near 24C.

In summer anticyclonic spells, Manchester can actually be warmer than a lot of people might normally expect.

I genuinely have no recollection of this. To me it seems that we've had temps well into the 70s for weeks and weeks without a gap.

I'm worried about my memory now!

I know you said that Rostherne wasn't representative of where you live but it surely can't be too far different. Anyway if you look at the data you will see that there were quite a few days that failed to reach (or even approach) 24C in mid-June.

I'm not going to argue that my memory is more reliable than stats submitted by various people, so I fully accept what I've been told.

I just don't remember any cool period in June - although I was in Peterborough the weekend of the 15th/16th and focus had been on that (and, now I think about it, it wasn't hugely warm and had a cooling breeze, so it's probs just my recollection being rubbish)

The first third of June, as was the last third of May, was very warm here, we had temps into the mid twenties on good number of days. Brief 'cooler' period during mid-June before we were plunged back into the furnace. 

Having just consulted HadCET again, I note that May and June both had CET maxes in the top 5. July looks favourable for such an accolade too. Thinking of the Extended Summer maximum (May - September)  temperatures I would think that 2018 is shaping up nicely. 1989 would have to be in there, along with I suspect 1959 and 1949 and maybe 2006. Let's have a look.

We certainly could smash the CET average max temperature record for May-Sept this year if the current conditions keep going. 

Here are all the years where the MaxCET exceeded a mean of 20C for May to Sept:

1976 20.82C

2006 20.78C

2003 20.62C

1911 20.60C

1959 20.58C

1947 20.56C

1989 20.38C

1933 20.36C

1949 20.32C

1995 20.28C 

It was my son's first birthday the middle weekend of June and we were watching the forecasts carefully as the party was planned for outside. In the event the weather was OK for the day (Saturday 16th) although it wasn't too warm and there was a light five-minute shower. By the evening it got quite chilly and windy and there was rain overnight. Then there were more showers on the Sunday too - a month ago today and I think that's the last time it rained here.

Interesting Weatherwatch in the Guardian today

he “beast from the east” cold of late winter 2018 and the arid heat of the UK’s summer so far, are united by one pronounced meteorological phenomenon: atmospheric blocking. Large meanders in the jet stream often lead to the development of huge anticyclones – areas of high pressure that can remain stationary for weeks at a time.

Weatherwatch: traffic jams in the jet stream

Read more

A blocking area of high pressure, sitting over Scandinavia and western Russia in February and early March, maintained a static weather pattern and pulled in a conveyor of sub-zero air to the UK. Just four months later, blocking allowed high pressure to settle close to the UK. This has resulted in very warm and extremely dry conditions with some central and southern parts of the UK seeing no measurable rain for over a month.

Predicting when and where atmospheric blocking will take place is difficult, although there are some clues. One signal is solar activity, the levels of radiation, sunspots and other solar phenomena that ebb and flow on a periodic 11-year cycle. Studies have shown that, on average, a decrease in solar activity can promote an increase in atmospheric blocking, although the relationship is complex.

Brilliant- I think I thought you'd have the answer GW. How do you come up with it so quickly?

I must admit I didn't realise these years were all in such close grasp- I thought maybe 21s etc. It will be interesting to see whether this really is going to be the front-loaded summer; time is ebbing for that. 

In another post Roger 63 has drawn links between our late winter blocking and this prolonged spell. Another agenda, I agree, but I do wonder if there might not be downstream links between extreme SSWs and extended summer warmth. 

There’ll no doubt be a new generation of children who now in future will look back at the long sunny summers and proper snow in late winter ‘we used to have’.

It does make me wonder if we're back to the 80s weather pattern wise. There’s definitely been a change but will it last?

Yes the official data for June, including data from manual stations, is now available at this link:

https://digital.nmla.metoffice.gov.uk/download/file/sdb%3AdigitalFile%7C014c5c26-1ca8-4968-85a4-cb8a9e44efe6/

I also recently posted tables listing the maximum temperature for every day so far this year up to 30 June using the Daily Weather Summary (DWS) reports which can be found at this link

https://www.theweatheroutlook.com/twocommunity/default.aspx?g=posts&m=1014424#post1014424

Below is the updated list for June which now includes the manual data. Key point to note is that we did make 30C on the final day of the month, just, thanks to Cromdale. The highest reading from an automatic station was 29.5C at Otterbourne Water Works but that is now superseded.

This means that between 25 June and 9 July (15 days) we reached 30C somewhere on every day apart from 4 July. We will have to wait for the manual data for July to see if we did make 30C on the 4th somewhere but I think that is unlikely. Having said that it is unusual for Giants Causeway to have the highest temperature so it is possible that somewhere was higher than the 29.1C recorded at that location on 4 July.

To date, we have now recorded 16 days above 30C so far this year, all of which have come since 25 June. By way of comparison in 2006 we had a total of 18 days above 30C for the whole year. So not far behind 2006 with still nearly half of summer to go.

UK maximum temperatures

2018 maximums
June
1 26.8 Aboyne
2 25.9 Kinross and Oyne
3 27.1 St James Park
4 26.6 Porthmadog
5 23.2 Castlederg
6 24.3 Porthmadog, Gosport Fleetlands
7 24.9 Derrylincornahoule, Glasgow Bishopton
8 24.1 Ringmer
9 23.7 Belfast International AP (Aldergrove)
10 25.5 Porthmadog
11 26.6 Bournemouth AP (Hurn)
12 23.2 Plymouth Mountbatten
13 23.3 Heathrow
14 23.9 Heathrow
15 23.8 St James Park
16 21.6 Weybourne
17 20.2 Scampton
18 26.6 Heathrow
19 25.6 Writtle
20 26.3 Teddington (Bushy Park)
21 22.2 Preston Cove House (Dorset)
22 23.7 Ringmer
23 24.6 Boscombe Down, Larkhill, Usk
24 26.5 Heathrow
25 30.1 Hampton Water Works, Teddington
26 30.7 Rostherne
27 31.9 Porthmadog
28 33.0 Porthmadog
29 32.5 Porthmadog
30 30.0 Cromdale

Thanks for the list & link