Wildfires in southwest France have created a rare thundercloud. It formed from intense heat rising off the flames.

Officials say this has never happened before in France. The cloud type is called pyrocumulonimbus.

A spokesman for France's National Firefighters Federation confirmed it came from a large wildfire in the Gironde area. Until now these clouds had mainly appeared in Australia and North America.

The clouds are dangerous. They can push flames to spread faster below them.

Lightning from the clouds can also start new fires. Wildfires across France and Spain are still not under control.

Another heatwave is now approaching the region. Experts warn the heat could make the fires worse. Together the fires and heat pose a serious risk to both countries.