Firefighters have urged people to be careful after a patch of grass caught fire in Carshalton last night.
Hot dry weather has left grassy areas "like tinderboxes" meaning fires can start and spread easily in the undergrowth.
A crew from Wallington fire station was called to an 8m square patch of grassland in Dale Park Avenue which caught fire at around 7.50pm yesterday.
The firefighters used backpacks filled with water to deal with the blaze as it was difficult for them to get a hosepipe to it.
Crew manager Dan Coleman said: "There are signs someone's been there setting small fires, maybe having a barbecue or something, but it's like a tinderbox at the moment just waiting to catch fire.
"It could have been a discarded cigarette or a broken bottle causing the light to refract.
"The message is for people to maintain vigilance. If they have barbecues, make sure they're looked after and put rubbish in the bin when you leave."
The warnings come after an area the size of four football pitches caught fire on Mitcham Common yesterday. The London Fire Brigade has been dealing with an average of more than 20 grass fires a day in July and 1010 in total this summer compared to just 535 between May and July last year.
Firefighters tackle the Mitcham Common grass fire yesterday
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