Understanding
Forest fires: understanding the risk in France
Where is France on fire, at what time of year, why does a fire ‘explode’ on some days but not others — and how to read the Forest Fire Forecast like a pro. The foundation of knowledge that makes all the right reflexes obvious.
Key points
- A fire requires three elements (the ‘fire triangle’): dry fuel, oxygen and a heat source — prevention involves removing one of these three.
- Dangerous days combine heat, dry conditions and wind — a reminder from the fire service: the ‘rule of 30’ (over 30 °C, humidity below 30 per cent, wind speeds over 30 km/h).
- Forest Weather (Météo-France) indicates this risk using a four-colour system, department by department, for tomorrow and the day after tomorrow.
- The risk is no longer confined to the south: the season is getting longer and extending further north and west.
- Nine out of ten incidents are caused by human factors — the factor that everyone can influence.
The fire triangle, or why everything goes up in flames so quickly
A fire is simply a matter of chemistry: for a flame to exist and spread, there must be fuel (vegetation, which is all the more flammable the drier and finer it is — grass, pine needles, brushwood), oxygen (air, stirred up and carried by the wind) and ignition energy (flame, spark, hot surface, lightning). Remove one side of the triangle and the fire goes out: that is exactly what the brush cutting (less fuel), the good practices (no ignition source) and the fire brigade (cooling, smothering).
What turns a departure into a disaster is the propagation speed : a wind-driven bushfire travels several kilometres per hour, sends sparks flying hundreds of metres (known as ‘fire jumps’) and doubles in intensity as it climbs a slope — the vegetation above the flames is preheated and therefore ready to catch fire. Hence the survival rules detailed in our ‘during’ pages.
The ‘30-rule’: recognising a high-risk day
Fire services summarise high-risk days in a simple memo — when all three thresholds are exceeded, any fire can get out of control:
Add the chronic drought (weeks without rain that dry out the vegetation right down to the roots) and there you have the recipe for those days when cigarette ends, angle grinders and barbecues become a serious hazard — the ones the Forest Weather Service colours orange or red.
Read the Forest Weather Forecast
Published daily during the season by Météo-France (at around 5.00 pm, for tomorrow and the day after tomorrow), the Forest weather combines temperature, humidity, wind and vegetation dryness into a single hazard level for each department:
Green — low
Low risk. Basic precautions are still advised (a grass fire is always a possibility).
Yellow — moderate
Increased caution: roadworks in the morning; be careful with cigarette ends and barbecues.
Orange — high
Work involving sparks and outdoor cooking fires is postponed; flowerbeds may be closed; hiking routes have been revised.
Red — very high
Lowest risk: no high-risk activities, mountain areas largely closed; please remain alert to warnings and smoke.
The Forest Weather Forecast indicates the risk meteorological — not current fires. For information on these, please see our real-time map, based on verified reports. And for today’s details for your department :
[fdf_risk_map]Where and when is France on fire?
- The Mediterranean Arc (Provence, the coastal region of Occitanie, Corsica) remains the area most at risk: fire-prone vegetation (garrigue, maquis, pine forests), dry summers, the mistral and the tramontane. This is where the fastest-spreading fires occur — including the Aude fire of August 2025, the largest since 1949.
- The Landes Massif : the largest managed forest in Western Europe, historically organised to combat fire (firebreak tracks) — and yet struck in 2022 by the major fires at La Teste-de-Buch and Landiras.
- The journey northwards : Brittany (the Monts d’Arrée, 2022), the Loire Valley, the Jura, and stubble fires right on the outskirts of towns in the Paris Basin. Smaller areas on average, but regions that are ill-prepared — both in terms of their inhabitants and their landscapes.
- The timetable is getting longer : The peak season is in July and August, but spring fires (caused by dead winter vegetation, before new growth) and autumn fires (caused by prolonged droughts) are becoming increasingly frequent. In the mountains and in the north, these ‘off-season’ fires are the most unexpected.
The underlying driver is climate-related: longer droughts, more frequent heatwaves, and stressed vegetation. Projections from Météo-France and INRAE are consistent: the area at high risk is expanding, and the season is getting longer. Detailed, year-by-year data can be found on our page key figures and themapped history.
The human factor: the only one that everyone can influence
Drought and wind cannot be decreed ; but the outbreak of fires can : 9 out of 10 are man-made, and more than half are down to simple carelessness. That’s the whole point of this hub: the everyday actions eliminate the ignitions, the brush cutting removes the fuel from around the houses, the crisis responses protect lives, and thealert ties it all together. An informed citizen is, quite literally, a firewall.
The risk changes every day. So do your reflexes.
Check the fire alert status for your department, keep track of current fires and report a new fire via the Feux de Forêt mobile app.