Devastating European wildfires in maps - and how they're being tackled

The fires have become so extreme they have created their own giant fire thunderstorm.

A rare weather event, storms like these are formed when heat from the wildfires makes the air above the fire rise rapidly, carrying smoke, ash and water vapour high into the atmosphere.

As the air rises, it cools, and the water vapour condenses into a cloud. If the fire is powerful enough and the atmosphere is unstable, that cloud can grow into a cumulonimbus - the same type of cloud associated with thunderstorms.

If these clouds then become large enough, they can produce their own lightning, which can then start new fires. They can also occasionally bring hail and rain.