Eight fire engines and around 60 firefighters tackled a grass fire on Cranford Lane in Harlington.
Around 14 hectares of grass and shrubland across three separate fields were damaged by fire. There were no reports of any injuries.
A London Fire Brigade spokesperson said: "The recent dry weather has made the ground extremely dry, which unfortunately means grassland and parks will burn quickly when exposed to even the smallest of sparks.
“Common causes of grass fires include carelessly discarded cigarettes or matches as well as rubbish left lying around such as glass bottles, which can start flames by magnifying the sun’s rays.
“Every one of us can help reduce the risk of fire and keep our communities clean, make sure rubbish is safely thrown away and cigarettes are always properly disposed of.
“If you see a grass fire, don't attempt to put it out yourself as grass fires can travel very quickly and change direction without warning. If you see signs of smouldering grass then call the Brigade and let us know where the fire is.”
The Brigade was called at 2130 and the fire was under control by 2349. Fire crews from Hayes, Feltham, Heathrow, Hillingdon, Southall and surrounding fire stations attended the scene.