Considering we are under Pm Atlantic air at the moment, temperatures have been notably high for such an air mass. Yesterday after the rain had cleared, my station got up to 24C in brightness and today I'm already up to 23.4C. Normally, you'd never expect Pm air to reach more than 20C in the Manchester area, especially when its breezy.

My guess is it must be all the residual warmth of the last two months in the ground and in the air.

I would say that this is probably down to residual heat, and that is something which I have commonly seen here in Edinburgh during a decent summer.

What tends to happen then is that a cold front might move through and introduce cooler and fresher air (which is that Pm air mass that you have mentioned) and then behind that, the temperature here in Edinburgh might still get up to around 21ºC here in Edinburgh. Yet in a poor summer, the temperature will tend to be no better than around 16-17ºC under the same type of air mass.

Furthermore, we would probably also need to consider the fact that this is actually a returning Pm air mass rather than a true Pm air mass. That is important because although both of those air masses come from the same source and have the same characteristics (they both bring a mixture of sunshine and showers), a returning Pm air mass is approaching us from the SW or SSW whereas a true Pm air mass would be coming at us directly from the west or NW.

This means that a returning Pm air mass is bound to have warmed up a bit more than a true Pm air mass before it reaches us, as a result of it reaching us from more southerly climes. That in turn would then cause the temperature to be that wee bit higher as well.

During this hot weather, when I run my cold water early in the morning, it doesn’t run cold, in fact it’s quite warm.  So I assume it’s picking up residual heat from the ground while it’s stood in the mains pipe overnight.  Later in the day, it does run colder, once everyone else on the same mains system starts running it.

Despite this cooler weekend, it was still running less than cold this morning, so there’s still residual heat in the ground. 

GFS 12z op run looking good so far. UKMO less so.

Or perhaps the SSTs are higher than average due to the prolomged warm weather and the airmass is therefore warmer that it otherwise would have been?

Temperatures are certainly not any warmer than they would otherwise have been here. A cool 15C yesterday under rain and average 19C under sun today. Standard temperatures for the given conditions under such an airmass.

Manchester Summer Indices

Summers in order with the best at the top and the worst at the bottom 

1976 301
1995 298
2018 286 (up to 31st July)
1983 278
1955 277
1911 274
1984 271
1959 269
1975 268
1949 267
1989 262
1947 255
1933 251
1901 249
1921 249
2003 247
2013 247
1925 246
2006 246
1996 245
1935 243 
1994 240
1934 238
1940 238
1941 236
2014 236
1970 235
1969 234
1973 234
1999 234
1997 232
1990 229
1917 228
1926 227
2005 224
1905 223
1932 223
1945 223
1967 223
1977 223
1914 222
1992 222
1908 220
1960 217
1950 216
1957 216
1968 215
1906 214
1942 214
1937 213
1939 213
1904 212
1929 211
2001 211
1903 209
1943 209
1991 207
1913 205
1971 205

Final value of Manchester Summer Index if  August 2018 is identical to these past unimpressive Augusts

August 1985: 256

August 1986: 257

August 1992: 276

August 1994: 280

August 1999: 279

August 2004: 272

August 2006: 261

August 2008: 261

August 2009: 268

August 2010: 262

August 2011: 261

August 2014: 260

Manchester Summer Indices

 Summers in order with the best at the top and the worst at the bottom 

1976 301
1995 298
2018 286 (up to 1st August)
1983 278
1955 277
1911 274
1984 271
1959 269
1975 268
1949 267
1989 262
1947 255
1933 251
1901 249
1921 249
2003 247
2013 247
1925 246
2006 246
1996 245
1935 243 
1994 240
1934 238
1940 238
1941 236
2014 236
1970 235
1969 234
1973 234
1999 234
1997 232
1990 229
1917 228
1926 227
2005 224
1905 223
1932 223
1945 223
1967 223
1977 223
223   <-------------------------if rest of August has a mean max of 15C, zero sunshine, rain everyday.

Do you or anyone else has this for Heathrow? 

I've come to bloody hate front-loaded summers.

Hoping the latest GFS doesn't come off though. Some hideous autumnal charts after day 7 on that one.

I don't think I've seen the sun since the first part of my commute in. I'd rather have 22c and clear blue skies than 25c and cloudy.

To be fair, given some of the weather conditions that August has been capable of producing in recent years, I think 25C and a bit of cloud is not bad. Could certainly be worse, and it could get much worse if the models are right.

It's not been too bad here at work near Birchwood today. More sun than a lot of other recent days anyway! Just wish there was more to look forward to. As much as people are clinging onto hope, it seems like the models are on a downward trend. Ah well. We might got our usual nice September where no one can believe it is so warm in September even though it happens nearly every year

Looking at the greatest summer max temp anomalies this decade and what a surprise the top 3 are all negative.

1. June 2012, -2.7

2=. July 2011, -2.2

2=. July 2012, -2.2

4=. July 2013, +2.0

4=. July 2018, +2.0

Figures for rainfall and sunshine anomalies would show an even greater bias towards bad.

Average max and mean for July 2018 at Aberdeen Airport was the second warmest in at least the last 30 years. Beat both July 1995 and 2003. Only 2006 was warmer.

It's also notable that while the second half of July was wetter it didn't correspond with a cooldown in temperatures as normally happens if anything it was warmer. 

Manchester Summer Indices

Summers in order with the best at the top and the worst at the bottom 

1976 301
1995 298
2018 292 (up to 5th August)
1983 278
1955 277
1911 274
1984 271
1959 269
1975 268
1949 267
1989 262
1947 255
1933 251
1901 249
1921 249
2003 247
2013 247
1925 246
2006 246
1996 245
1935 243 
1994 240
1934 238
1940 238
2018 237 <------if rest of August records zero sunshine, rain everyday and a mean maximum of 15C

A wonderful 28C under sunny skies in Manchester today! It's not been this warm in August since 1 August 2013, further highlighting the recent mediocrity of the month even more.

Even spent the evening having an ice cream on the beach in Lytham St Annes.

The thing that standouts for me about this summer and indeed since mid April is the amount of sunshine that there has been. A quick review of all my timelapses there has only been two days where the sun hasn't even put in just a brief glimpse, 24th April and 25th May. The number of times I have caught the sun setting in the west in that period has been remarkable. 

Overall, it has been a sunny year thus far.  

a real front loaded summer means a beautiful May and/or June, even a nice Easter then nothing but utter tripe with a seamless blend into Autumn.

whatever happens now, this certainly is not going to be front loaded.

There was a pretty decent display of nocitlucent clouds before dawn this morning and pretty high up in terms of altitude. That is pretty late in the season to still be seeing these clouds. An indication that something unusual about this summer. 

As I suspected this (extended) summer not only is up there with 1976 and 1995, but it actually has stronger blocking. First image shows 500mb differences for May-July between 2018 and 1976 and 2nd figure is 2018 minus 1995. Very impressive and almost confirmation of the best summer of our lives! Let's see what August brings and what the MJJA averages will look like.

My 30-day sunshine total peaked at 286.1 hours on 8th June which is mostly spring. Largest 30 day total wholly in summer was 265.4 hours up to 4th July. 

Sadly it's been in freefall lately and down to a bog-standard 162.4 hours for the past 30 days. Second half of summer could well end up duller and wetter than last year. Currently it's running wetter but also sunnier though not a lot in it really. 

16th July - 7th August 2017

Sunshine: 121.2hrs

Rainfall: 46.8mm (12 rain days)

16th July - 7th August 2018

Sunshine: 133.0hrs

Rainfall: 61.8mm (15 rain days)

Not a patch on 1976, 1995 or 2003.

What people forget is that this summer has also had the advantage of an exceptionally warm spell in April, and a remarkably warm, dry and sunny May. Both 1976 and 1995 failed to deliver either of those, at least nowhere to the extent of this year. Throw in a warm September, which again neither 1976 or 1995 saw, and we will have one truly astounding summer!

Who'd have guessed?