Glastonbury festival-goers should brace themselves for "torrential thunderstorms" over the weekend, forecasters have warned.
Michael Eavis opens the doors of his 900-acre home in Somerset on Wednesday as thousands arrive early for the music and performing arts extravaganza.
But forecaster Meteogroup, weather division of the Press Association, warned that Wednesday's sunshine could soon give way to bursts of heavy rain liable to turn the site "very muddy".
Meteogroup's Rachel Vince said: "Tomorrow is not looking too bad at all with lots of glorious sunshine. There will be only a light breeze so pitching tents shouldn't be a problem.
"Thursday should be generally dry with sunny periods although there is a threat of thundery showers which can't be ruled out. The temperature will be around 22 degrees centigrade, though."
But on over the following days, when headline acts like Lily Allen, Neil Young, and Bruce Springsteen take the stage, fans could get very wet.
Ms Vince said: "Unfortunately, on Friday and Saturday Glastonbury could be in the line of fire from thundery showers. It could be torrential thunderstorms at times. There should be periods of sun between the showers. That's that nature of summer in the UK.
"The advice is to pack your wellies and your sunglasses."
Festival spokesman John Shearlaw said: "The last thing people are thinking about it the weather. Glastonbury has been going for 39 years. What can you do? The festival isn't God. You can't sit around waiting for the weather.
"People are coming earlier and earlier - maybe at last half will come tomorrow. The preparations are sound and we can't wait to start!" THE PRESS ASSOCIATION