People have reported thick smoke over Guildford, Woking, Addlestone and on the M25 near Chertsey.
Image source, Alan JohnsonA large grass fire has been declared a major incident by firefighters in Surrey.
The fire brigade has several fire engines at the scene of the blaze at Hankley Common, near Farnham.
People have been warned to avoid the area because of the large amounts of smoke and to keep windows and doors closed and pets inside.
People have reported smoke over Guildford, Woking and Addlestone and on the M25 near Chertsey.
Fire crews tackled a blaze on the same stretch of land on Wednesday when four hectares of Hankley Common near Elstead caught fire.
After that incident, the fire service warned that despite overnight rain, more warm weather was expected and vegetation remained extremely dry, and the public were urged not to use barbeques and to take care.
During the heatwave earlier this week, fire services across the country were under pressure as 15 areas around the UK declared major incidents following multiple blazes.
Please avoid the area to allow our crews to work. Stay out of the smoke and far away from the fire as it can travel quickly.
— Surrey Fire & Rescue Service (@SurreyFRS)
London had its busiest day since World War Two, the city’s mayor said.
After social media users started posting footage of the blaze, Surrey Fire and Rescue Service tweeted: “Please avoid the area to allow our crews to work. Stay out of the smoke and far away from the fire as it can travel quickly.”