Even in London the average night time minimum is 10C, meaning most other places it will be single figures. You are looking at exceptional warm spells to still feel warm late in the evening. I do think there's an element of wanting payback for such a horrific March and to a lesser extent April, but that's getting in the way of enjoying some very reasonable weather. Here locally it's been a good 2 weeks of sunny spells or near cloudless days with mostly average or slightly above average temperatures and the odd day like today 3-5C above average. Very happy with May personally, will give it a 7.5/10. I think there would be less complaining if this May had come in a year that had a few warm spells in March and April.