Although certainly not last year and in fact not frequently despite it being a oft-repeated myth on here!

I think the effect is more noticeable in the west and north of the Midlands. 2006, 2013, 2014 were the most notable, with August tanking after very good June/July spells.

Even in 2018, August was the worst month out of that May/June/July/August period (May, June and early July were the best, with an easterly feed dominating)

This is a superb chart, and typical of much of May/June/early July 2018:

GFS has be churning out charts similar to this recently.  Could easily happen this year.

I have seen people comment on this forum on a number of occasions that there hasn't been a notably good August in the UK since 2003. I would certainly subsribe to that view on the basis of the weather I have experienced in many Augusts in my part of the world.

What I recall about August 2003 here was that the hottest weather seemed to peter out after mid-month, although it was still settled for most of the time. While the first half had some high nightime minima here, the nights in the second half of the month were generally quite a bit cooler.

Looking properly wet over South Wales and Dartmoor, though.

It always amazes me how much wetter the West can be compared to the East on our tiny little island. 

indeed the downgrades are starting in earnest this morning. WeatherPro now only gives 11mm for my location (was 16mm as recently as yesterday), with the rain clearing by lunchtime. I wonder how much further that will fall? 

We are extremely well over due for some warm hot weather that we haven't seen one this Spring and more like Icelandic climate here where temps stuck at single digits to low teens rain or shine.  Models need to realized we are now heading to summer month soon so must start giving us warm hot charts eventually and well much sooner than later.

16-dayer showing the temps gradually improving over W Europe but even into week 2 still below average for the time of year. Wet for week 1 but dry in week 2, a change from previous forecasts

GFS - LP moving in Sun 9th 970 mb SW Ireland, staying around and filling to Thu 13th. Although it drags up some warmth for the SE at first, it ends up as a cool pool later on. That sinks a little further south but is unusually persistent, essentially n place for 10 days, encouraging E-lies over the south but something milder from the Atlantic over Scotland.

GEFS - burst of warmth with rain in SE tomorrow, then a long period with temps close to or a little below norm, and rain in most runs from time to time (no drier period as above). The control run for Scotland shows a couple of periods with cold outliers 15th and 20th.

ECM - rather like GFS but the cold pool links up with LP on the Atlantic preventing warmth reaching Scotland

I think we got 23c , a couple of lovely days and ended on the Thursday 

Now 6.9mm. The epic “copious rainfall” spell continues...

Here it has been very wet this week, and looks exceptionally so tomorrow, along with large swathes of the UK. Flooding a very real possibility too with upwards of 100mm being forecast in some parts of Wales.

Yes, the 8 to 16 day range has downgraded the warm up, even in eastern Europe. Looks like slow, erratic, uncertain progress through late spring with no hints of summer yet.  

Aah but most people live in the South East  (I'll get my coat) 

Indeed it looks very wet over the hills of Wales where very few people live. In the populous SE, which is crying out for meaningful rain, not so much. My garden is a dustbowl again. I am hoping for 15mm as promised. Yet it now looks nearer a third of that. Downgraded yet again – when will we ever learn? 

It's true though – far more people live in SE of England than in Wales and Scotland combined. And for those millions of people, tomorrow's much-vaunted epic rainfest now looks like yet another downgrade. The rain is massively needed – but it's not looking like delivering at this juncture. 

Jetstream running across the S of the UK, at first directly then as part of a loop. From Wed 12th it switches to a more S-ly track and continues there for a week, occasionally looping up and around the UK to support LP close to S England. Final frames show a more fragmented stream, but with one fragment or another affecting some part of the UK. Not good either for warmth or dryness.

16-dayer has gone back to being wet in the south at last for week 2, since yesterday's forecast.

GFS Current LP decays over Britain to Sat 15th, followed by a week of slack HP around the UK, centred mainly to N and E, before significant LP appears mid-Atlantic to pump up air from the S (esp into SE England). This does not by a long way match the jetstream model!

GEFS briefly warm , then cool for S England to Sat 15th but in NW nearer norm through this period, after which mean near norm but with increasingly large spread. Some rain appearing irregularly in most runs. 

ECM never develops the HP after Sat 15th and by Tue 18th is showing slack LP instead centred N Ireland

Are you sure? How much rain have you measured this week?

Here we've seen 11mm today which is less than half what I'd (half) hoped we would see. The dry spell hangs on here, and all I expect this week is the odd light shower.

Moving on to today, we have measured 11mm since 3.30am and it's still pouring, and so that's 30-plus mm so far this week and a lot more to come today.

Rain band starting to clear out of the SE already. Dry by noon?

Recent Arpege forecasts were spot on for here. 10.4mm so far today. I put down the Evergreen yesterday on the basis of 11mm falling from this event.

https://www.theweatheroutlook.com/twoforecasts/hourly-weather-forecast.aspx?loc=Berkhamsted