Brossac fire, August 2025 Brossac, Saint-Vallier
The fire started on 12 August 2025 in Brossac, France, and satellites saw it burning for 1 day. Copernicus mapped a burnt perimeter of 170 hectares from satellite imagery, spread across 2 municipalities.
Number 17 in France in 2025, of 23.
The power measured by the satellite is low (8.4 MW in the strongest hotspot), more typical of grass or stubble burning, or a slow surface fire, than of a large crown fire.
- Burnt area
- 170ha
- Copernicus perimeter
- Duration
- 1day
- 12 Aug 2025 – 12 Aug 2025
- Municipalities hit
- 2
- communes
- Started on
- 12 Aug
- 2025
- Heat detections
- 5
- in a single hotspot: 8 MW
- Danger at start
- 39
- Very high · FWI index
- Energy released
- 17MW
- sum of detected power
Where it burned
How it evolved, day by day
Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.
The weather it burned in
It had gone 10 days without rain (1 mm or more) when it started. Rain came after the fire: 3.4 mm on 20 Aug.
This area had burned before
No earlier perimeters overlap this fire since 2016, when the satellite record begins.
What happened to each town
-
137 ha reached on 12 Aug6.3 %
-
Saint-Vallier 139 inhabitants · 0.9 km from the town33 ha1.8 %
Burnt area inside each municipality, from crossing the official perimeter with administrative boundaries. The distance is from the town centre to the nearest fire: staying a kilometre away does not mean it reached the houses.
What burned
- Scrub and transitional woodland41 %
- Coniferous forest40 %
- Agricultural areas8.1 %
- Mixed forest6.4 %
- Artificial surfaces4.6 %
Land cover inside the perimeter according to Corine Land Cover, as reported by Copernicus.
Official record
According to BDIFF, a fire of 201 ha was recorded in Saint-Vallier on 11 August 2025 (the satellite measured 170 ha). The record has no coordinates, so it was matched by municipality and date.
- Saint-Vallier 11 August 2025 · 16:25 201 ha
BDIFF (Base de Données sur les Incendies de Forêts en France). This is the agency’s consolidated statistic: it measures the area in its own way, which is why it can differ from the satellite.
The weather day by day
ECMWF ERA5 reanalysis at the fire location, the standard reference for past weather, and the Canadian Fire Weather Index (the same system Copernicus uses), computed by WorldFires from that data. Days after the fire run until the first rain.
Open-Meteo.com (CC BY 4.0) · Copernicus Climate Change Service (ERA5)
| Day | High | Min. humidity | Peak gust | Rain | Danger (FWI) |
|---|---|---|---|---|---|
| 12 Aug | 38.3 °C | 24 % | 20 km/h | 0.0 mm | Very high 39 |
| 13 Aug after | 32.1 °C | 36 % | 30 km/h | 0.1 mm | Very high 41 |
| 14 Aug after | 34.7 °C | 35 % | 20 km/h | 0.0 mm | High 29 |
| 15 Aug after | 39.2 °C | 20 % | 22 km/h | 0.0 mm | Very high 40 |
| 16 Aug after | 38.1 °C | 29 % | 24 km/h | 0.0 mm | Very high 40 |
| 17 Aug after | 33.0 °C | 35 % | 23 km/h | 0.0 mm | High 32 |
| 18 Aug after | 24.3 °C | 52 % | 31 km/h | 0.0 mm | High 25 |
| 19 Aug after | 24.7 °C | 49 % | 31 km/h | 0.6 mm | Moderate 20 |
| 20 Aug after | 23.5 °C | 55 % | 25 km/h | 3.4 mm | Low 6 |
Before and after, from space
Drag the line to compare the same ground before the fire and after it.
If the day is cloudy, change the date: each satellite passes once a day. In false colour the burnt ground looks brown or red.
The smoke
CAMS · CopernicusOn 14 August 2025 the air beside the fire reached 27 µg/m³ of PM2.5. That day averaged 16: 1.1 times the WHO daily guideline (15).
Particles from the Copernicus CAMS model at the centre of the perimeter; these are not measurements in each town. The pale bar is the worst hour, the solid one the daily average.
Open-Meteo.com (CC BY 4.0) · Copernicus Atmosphere Monitoring Service (CAMS)
Detections table · 5Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
Frequently asked questions
- How long did the Brossac fire last?
- Copernicus dates it between 12 August 2025 and 12 August 2025: 1 day between the first and last image with fire.
- How much area did it burn?
- The perimeter Copernicus measured from satellite imagery is 170 hectares (1.7 km²). Official national figures may differ.
- Which municipalities burned?
- The fire entered 2 municipalities: Brossac (137 ha, 6.3 %); Saint-Vallier (33 ha, 1.8 %).
- Did the fire reach a town?
- The closest fire to a town centre came within 0.9 km of Saint-Vallier. That is the distance to the perimeter or nearest hotspot; it does not mean it entered the houses.
- What was the weather like?
- During the fire the temperature reached 38.3 °C, humidity dropped to 24 % and gusts hit 20 km/h. The fire danger index (FWI) reached 39, class Very high.
- Where does this data come from?
- From the EFFIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of France (geoBoundaries). It is not an official report.
Where to verify it
A satellite detection is not an official report. Final figures and the fire’s status are published by each country’s emergency service.
Emergency number: 112 · 18
Satellite cross-check
Does something look wrong on this page?
This page is built from satellite data and official records, and it sometimes gets things wrong: the wrong dates, the wrong town, two fires merged into one, or something that was not a wildfire at all. If you know this fire first-hand (you live nearby, saw it, fought it or reported on it), tell us what really happened and we will check it.
Report an error
Where this data comes from
The perimeter and land cover come from the Copernicus European Forest Fire Information System (EFFIS), measured on MODIS and Sentinel-2 imagery and published under CC BY 4.0. Heat detections come from the VIIRS sensors aboard Suomi-NPP and NOAA-20, distributed by NASA FIRMS at 375 m resolution. Municipal boundaries come from geoBoundaries ADM5 (Open Data Commons Attribution License 1.0). The area per municipality is computed by WorldFires by crossing the perimeter with those boundaries, so it may differ slightly from each country’s official figure.