One Swallow Doesn't Make a Summer

We Brits seem to note the weather only when it deviates from our concept of 'nice'. Now, one extreme weather event doesn't confirm that climate change is here (but climate change will be an accumulation of such events). Yesterday (9th May) was very odd in my home town of Loughor. It started and finished with unseasonally hot conditions ('nice' but hardly worth a comment?) but was interspersed with a violent thunderstorm that delivered an inch of rain in an hour along with hailstones that were almost the size of 5p coins. The storm and the downpour appear to have been very localised, being confined to a few square miles.