Considering the temperateness of the English climate, it's amazing how much mileage the locals get out of the subject - a two-day cold snap is discussed as if it were the onset of a new Ice Age, and a week in the upper 70s starts rumours of drought. The fact is that English summers rarely get hot and the winters don't get very cold, though they're often wet. The bottom line is that it's impossible to say with any degree of certainty that the weather will be pleasant in any given month. May might be wet and grey one year and gloriously sunny the next, and the same goes for the autumnal months - November stands an equal chance of being crisp and clear or foggy and grim.

As far as crowds go, tourists stream into London pretty much all year round, with peak season from Easter to October, and the biggest crush in July and August, when you'll need to book your accommodation well in advance. Costs, however, are pretty uniform year-round