The weather in the UK, is so damn unpredictable, on Thursday the temperatures are north of 15 degree Celcius, and on Sunday there is snow. As one friend had rightly pointed out, "Never go short vol(ality) on UK weather"
Again today there was heavy snow (about an inch) till noon, while in the evening at 5PM it is bright and sunny all over again. (Though it looked nice and bright, with lots of sunshine, it was a bit too cold outside)
As it is said in Chaos Theory a butterfly flapping its wings in rain forests of Brazil, might cause a storm in India. Well if that is true, I am sure there might be a bunch of butterflys flapping their wings somewhere, which causes total chaos of the weather in London.
(Though I guess there are reasons for the weather to be so volatile here, I guess it is just too volatile for a person coming from a place where is summer for 8 months and rains for 4, with little variations)