Firefighters are battling a grass fire the size of three football pitches off Halcot Avenue in Bexleyheath.
A large expanse is ablaze on a stretch of open space which runs to Hall Place in the south.
London Fire Brigade have 25 firefighters are on scene on what could be the hottest day ever recorded. Temps of 38c are being recorded in parts of the country.
Four fire engines are also on scene.