Sunshine greeted Glastonbury revellers on Wednesday as Worthy Farm threw open its gates for the music festival but rain forecast in coming days means the traditional mud is set to return at the weekend.
"There's a steady flow of arrivals. Spirits are high," said the @GlastoLive Twitter feed.
Headline acts scheduled to perform as this year's musical extravaganza range from Metallica, Kasabian and Arcade Fire to veteran country singer Dolly Parton.
Thousands of people are predicted to arrive on Wednesday to find a good pitch for their tents on the 1,200 acre site before the first of the star performers take to the stage on Friday.
Forecasters say the recent fine weather is not set to last, with heavy downpours expected from late Thursday.
John Griffiths of Meteogroup said the fact that the ground is currently hard due to the lack of recent rain will not make much difference because of the amount of rain expected to fall.
"If it was just a few showers, the hard ground would make it drain off," he said. "But with three days-worth of rain due, it will get quite muddy, I suspect."
Car parks were opened from 9pm on Tuesday to allow festival-goers to arrive throughout the night when traffic volumes were low, but they were not allowed to leave their cars.
The gates at Glastonbury opened at 8am on Wednesday.
Elbow, Paulo Nutini and Kaiser Chiefs are among Friday's opening line up on the various stages around the vast site.
Tickets for this year's Glastonbury Festival sold out in the record time of one hour and 27 minutes.
Around 120,000 went on sale, with more than one million people registering an interest.
Including performers, workers and volunteers, the total number of people on site will reach around 175,000.
Festival founder Michael Eavis defended the inclusion of heavy metal band Metallica in the schedule.
"We have been going for so long that people don't expect us to put on a heavy metal band.
"We had Rage Against The Machine and we have had lots of fairly heavy metal bands in the past but this is not a typical headline.
"We usually have bands like Radiohead, Coldplay and U2, the Rolling Stones, but I am really looking forward to them.
"There's no other band in the whole history of the festival that has been so keen to play. They will do the best set of their lives here."
The English National Ballet will make their Glastonbury debut by opening the Pyramid Stage on Sunday with their performance of Akram Khan's Dust.
The Left Field area will see a tribute to Labour stalwart Tony Benn, who died earlier this year.