Ten fire engines and around 70 firefighters tackled a grass fire on Rammey Marshes in Enfield.
Around one hectare of grassland was damaged by fire.
A London Fire Brigade spokesperson said: "We've been seeing a 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.
"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 1243 and the fire was under control by 1513. Fire crews from Enfield, Chingford, Edmonton and surrounding fire stations attended the scene.