Fifteen fire engines and around 100 firefighters were called to a grass fire in fields surrounding a school on Turkey Street in Enfield.
An area of grassland measuring around five hectares of heathland was destroyed. No properties were affected by the fire.
Station Commander Dean Wilkinson was at the scene, he said: "The fire spread to a field with two horses. Firefighters worked hard in hot conditions to put out the fire in the field and the horses were moved to safety.
“This summer has seen an unprecedented long, dry spell with high temperatures so the grass in London is tinderbox dry and the smallest of sparks can start a blaze which could cause devastation.
“Despite our continued warning over the last few weeks, we know there are still people who are barbecuing in parks, dropping cigarettes out of car windows and leaving rubbish lying around.
"We are asking Londoners to help us protect the city we all love by doing everything you can to prevent further grass fires. Please don’t barbecue in open spaces or balconies, throw your rubbish away safely and put your cigarettes out properly.”
The Brigade was called at 1308 and was under control by 1718. Fire crews from Hornsey, Shoreditch, Holloway, Homerton and surrounding fire stations were in attendance.
The cause of the fire is under investigation.