Well all these recent weather extremes taken together certainly seem to point in one direction...However, I lived in London and thereabouts for most of the 70s and 80s and I do recall apocalyptic rainfall every now and again, and then there were the summers of '76 and '83...

We've had a lovely sunny day in Cornwall today with a pleasant 21.6C. Yesterday was also sunny after a damp early-hours, with 23C. No showers, no thunder, no big hail. It's usually the other way round twixt us and the south-east, so pardon me as I guffaw in a London direction...