French firefighters have confronted pyrocumulonimbus clouds for the first time while battling a wildfire in France.

The fire clouds, also known as cumulonimbus flammagenitus, develop when intense heat from ground fires causes rising air to cool and form a turbulent cloud that can generate its own winds and lightning. The phenomenon has previously been recorded in Australia and North America, and NASA has described the clouds as a fire‑breathing dragon of clouds.

According to Lieutenant Colonel Eric Brocardi, the extreme ground temperature at the fire’s core forces hot air to rise in a column that meets cooler air at higher altitudes, creating a pyrocumulonimbus that contains little moisture. The cloud can produce its own weather system, leading to spontaneous combustion of objects in its path and igniting embers on the ground with lightning.

The fire spreads unpredictably because the cloud creates shifting winds, resulting in multiple fire fronts rather than a single, predictable cone. Brocardi said the situation represents an operational difficulty, requiring a defensive approach and strategic retreat rather than direct confrontation.

Firefighters described the effort as an intense scenario in which they must prioritize safety and cannot control the fire’s direction, but they continue defensive measures, including protecting critical sites and rescuing animals, while awaiting possible rain.