Heavy rain in London is set to turn Wireless Festival into a mud-drenched weekend, with further downpours predicted for the weekend.
Scotland's T In The Park is set for similar storm weather, with certain parts of the UK likely to see a month's rain fall over the weekend and weather warnings in operation across the UK.
Wireless is set for rain today and tomorrow - with some sunshine amid the storms, and very heavy rain sweeping in on Sunday. Deadmau5, The Roots, Afrojack, Maverick Sabre, and Metric are among the artists performing today, opening this year's central London spectacular.
The British weather has already blighted several UK festivals this year, with Paul Weller forced to cancel his Jodrell Bank performance last month and Isle Of Wight festival all-but washed away as torrential rain swept the island.
Below: the must-see stars of Wireless 2012