The BBC provide a further update for those of you leaving really late.
Chris Fawkes from the BBC's Weather Centre said: "On Friday, the air will become very humid and the heat and humidity will combine for thunderstorms which although torrential, will be very isolated.
"It's an all-or-nothing forecast - if one hits Glastonbury it could make an absolute mud bath for the rest of the weekend, but could easily hit down the road and remain dry," he added.
Fawkes said although there could be some really heavy downpours, it would only last for around an hour and could be fine for the rest of the day.
"The weekend should be very warm, if not hot, with a lower risk of a shower," he said.