If I had to be choosy I’d go for 1st-19th June 2007, 20th-30th June 2012, 1st-20th July if either as both were diabolical, 21st-31st July 2012, and August 2012. The Julys of both were pretty poor but 2012 at least had a summery last third. June 2007 was more thundery and, while unsettled, August 2012 was the best month of that summer.
Re this summer, I think it balances out as average here, purely by pulling together extremes of wet (1st half of June), dry (late June and July), sunshine and temps. I recorded my coldest June day ever. August was, again, the least notable month - it’s never great or awful, although the first and final third were often fine and warm or hot. Just a shame the weather didn’t cooperate with key Bristol events, namely the harbour festival on 19th-21st July and balloon fiesta on 08th-11th August. Then again, Glastonbury was bone dry for once and the August bank holiday was lovely, better than 2017. Finally, it was also good to record some thunder this year. The real treat was that superb lightning storm that started late on my birthday (23/07) and went into the 24th.
Next year, I would like a much better June, more sunshine overall and a few more thunderstorms. Temperature wise it was a nice summer this year after the chilly May and start to June.