The 2015 Glastonbury festival is almost upon us and the question all ticket-holders are asking is: "Do I need to pack my wellies?" IBTimesUK has the definitive answer: "Maybe."

The Met Office forecast says that the ground should be dry as festival-goers arrive, but rain is expected on Friday afternoon as the remnants of Tropical Storm Bill reach Britain. How much rain? Well, that depends on whether Bill heads up north as expected, or decides to linger over the south west of England.

There will be sunny spells, with highs of around 20C, so we say pack your sunscreen and waterproofs, and do not pitch your tent at the bottom of a hill.

The importance of pitching your tent on higher ground was most clearly demonstrated at the 2005 festival, when camp sites were flooded after two months worth of rain fell in just a few hours.

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People's belongings float on the water in a flooded camp site on the first day of the 2005 Glastonbury festival, headlined by the White Stripes, Coldplay and Basement JaxxMJ Kim/Getty Images
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Tents are submerged in a flooded camp site on the first day of the 2005 Glastonbury festivalEddie Keogh/Reuters
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A festival-goer sorts through his mud-caked belongings on the second day of the 2005 Glastonbury festivalEddie Keogh/Reuters
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Andy and Liz from Yorkshire wallow in the mud on the first day of the 2005 Glastonbury festivalMJ Kim/Getty Images

Judging from the Met Office forecast, the weather this year could be similar to that at last year's festival, which started off dry until a huge thunderstorm forced all the stages to shut down for 90 minutes.

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Festival-goers splash through a muddy puddle after a sudden downpour at the 2014 Glastonbury festival, headlined by Arcade Fire, Metallica and KasabianCathal McNaughton/Reuters
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People wearing colourful wellies stand in the mud at the 2014 festivalMatt Cardy/Getty Images
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The mud-caked boots worn by IBTimesUK picture editor David Sim at the 2014 festivalDavid Sim

British summers being what they are, there is usually some rain at Glastonbury, though festival-goers rarely allow it to dampen their spirits.

In this gallery, we look back at some of the muddier years.

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A festival-goer jumps in a mud puddle on the second day of the 2013 Glastonbury festival, headlined by Arctic Monkeys, Rolling Stones and Mumford & SonsAndrew Cowie/AFP
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Harry, 2, is pulled through the mud on the second day of the 2013 Glastonbury festivalOlivia Harris/Reuters
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Site workers try to suck mud from the market areas close to the Pyramid Stage at the 2011 Glastonbury festival, headlined by U2, Coldplay and BeyonceMatt Cardy/Getty Images
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Tom Wilder, 17 from Kent, dives in the mud at Glastonbury 2011Matt Cardy/Getty Images
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A pair of Wellington boots are abandoned in the mud at Glastonbury 2011Adrian Dennis/AFP
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A festival-goer gets covered in mud near the main Pyramid Stage at the 2009 Glastonbury festival, headlined by Neil Young, Bruce Springsteen and BlurMatt Cardy/Getty Images
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A reveller crawls through the mud at the 2009 festivalMatt Cardy/Getty Images
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A mother carries her child through the mud around the Pyramid stage during the 2007 Glastonbury festival, headlined by Arctic Monkeys, The Killers and The WhoDylan Martinez/Reuters
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A toilet block is surrounded by mud during the 2007 Glastonbury festivalDylan Martinez/Reuters
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Two pairs of Wellington boots are seen in the mud during the 2007 Glastonbury festivalDylan Martinez/Reuters
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A reveller is dragged along in the mud in an inflatable boat at the 2007 Glastonbury festivalCarl de Souza/AFP
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Two revellers wrestle in a sea of mud at the 1998 Glastonbury festival, headlined by Primal Scream, Blur and Pulp Chris Helgren/Reuters