My thoughts for Summer 2011 -
June-
I think June will be settled initially with some coolish nights for the time of year but soon going down hill towards the June Monsoon which will last a good week or two.
After that rather unsettled showery weather.
I don't think it will be a cold month however.
July -
An unsettled changeable start, rather westerly and mobile in nature with rain fronts rapidly clearing away and long spells of sunshine in between.
Late July is possibly the best chance for a real hot dry period, potential here for high pressure to ridge strongly in and for front to be kept at bay. Possibly temps of 33c - 34c in the South of England for a SHORT period no record breaking temps or temps this high for a long period.
Thunderstorms moving in by the end of the month.
August -
Unsettled muggy start, few thunderstorms, temps pegged back to 25c - 27c, after the first week or so much fresher weather moving in from the Atlantic, temps back to 18c - 22c.
Rest of August pretty non decript I feel, temps high teens low 20's, showers at times.
Those I my first thoughts anyway, which will likely change.