Storm Alert: France — mistral, Cévennes episodes and Météo-France

The map below shows near-real-time precipitation and lightning radar. Switch to the warnings layer to check whether Météo-France has already issued a bulletin for your department.

If you want to know what time a storm will reach a specific town and how long it will last, use this site's storm tool — type in a town name and the module calculates a 12-hour forecast from the ICON-D2 model.

On the Côte d'Azur and in Provence, summer storms usually form in the afternoon, when strongly heated ground releases heat into the moist Mediterranean air. They tend to be violent but brief — 30 to 60 minutes of intense lightning and rain before the front moves on.

The so-called épisodes cévenols (Cévennes episodes), named after the Cévennes mountains in the southern Massif Central, are a completely different beast. Moist Mediterranean air hits the mountain barrier, rises and releases rain that can persist over the same spot for hours — with daily totals exceeding 200 to 400mm. They're responsible for the most dangerous flash floods (crues éclair) in the Gard, Ardèche and Hérault regions.

In Provence, summer also brings so-called dry storms — driven by strong mistral wind, with minimal rain reaching the ground but a real risk of lightning igniting dry vegetation. This is one reason southern France monitors storm and wildfire risk together.

Météo-France uses four colours: green (no danger), yellow (be aware), orange (be very aware) and red (absolute danger). The vigilance map is updated at least twice a day, more often in fast-moving situations. Warnings are issued per department, not for the whole country at once.

The FR-Alert system, which works via Cell Broadcast (similar to Poland's RSO or Germany's NINA/Cell Broadcast), sends notifications directly to phones in the affected area — no app needed, just a phone that's switched on with signal.

If you're camping in the Cévennes or the Ardèche during an orange or red warning, don't ignore it. Cévennes episodes can turn a calm stream into a raging river within minutes, and most fatalities in French flash floods are people who tried to drive through a flooded ford or were caught at a campsite in a river valley.

• Never drive through a flooded road — even 30cm of water can float a car.
• Campsites in river valleys in the Cévennes/Ardèche should evacuate on the warning, not wait for the water to arrive.
• In Provence during a dry storm with mistral wind — avoid forests, the risk of a lightning-ignited wildfire is real.
• Check the vigilance map before planning a route, not just the general weather forecast.

We've covered universal storm safety rules — shelter, cars, water — in more detail in a separate safety guide.