The world-famous festival is normally associated with rain and mud but today festival goers were unusually able to don summer outfits and sunglasses to bask in the sun.
Some enjoyed the beautiful weather by stretching out on the grass in bikinis, t-shirts and shorts.
While others kept cool in the sweltering conditions by sheltering under sun umbrellas and sucking on lollies.
Around 175,000 people are expected to pour through the gates of the festival which tipped to be the hottest ever by weather forecasters.
Some of the acts were baffled by the unusually high temperatures, with American folk rock band The Lumineers saying they “didn’t know how to act” in the hot and dry conditions.
Speaking before their performance, drummer Jeremiah Fraites, said: “It was raining so heavily during our set last time and this time it’s sunny, and it’s a little taste of home in Denver where the weather is always drastically changing.”
To give festival-goers respite from heat Glasto organisers have been handing out suntan lotion and water bottles.
Paramedics from South Western Ambulance Service NHS Foundation Trust has already treated 70 people at the festival, mostly for heat stroke.
A spokeswoman for the trust urged festival-goers to stay hydrated and to cover up, put on sunscreen, wash their hands and be hygiene aware.
The likes of Sheryl Crow, Lauryn Hill and headliner Stormzy are gracing the stage today in what festival organiser Emily Eavis says are ”perfect conditions”.
Miss Eavis added: “It feels so lucky because last week it looked like there were going to be the worst storms.
“Now there’s not a cloud in the sky. It’s amazing,” she told the Zoe Ball Breakfast Show on BBC Radio 2.
On the bill for the rest of the weekend will be Tame Impala, The Killers, Janet Jackson and Kylie Minogue.