Eight fire engines and around 60 firefighters tackled a blaze at a sports pavilion in Tentelow Lane, Southall.
Part of the sports pavilion was alight.
Station Commander Brett Loft, who was at the scene, said: "Crews worked hard to bring this fire under control. Due to the weather conditions the fire has created a lot of smoke in all directions and nearby residents are advised keep their doors and windows shut."
Firefighters are likely to remain at the scene for some time damping down any remaining hotspots.
The Brigade was called at 0237 and the fire was under control by 0657. Fire crews from Southall, Heston and surrounding stations were at the scene.
The cause of the fire is under investigation.