Lassance fire, September 2025 Lassance, Três Marias
The fire started on 30 September 2025 in Lassance, Brazil, and satellites saw it burning for 11 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 10,428 hectares from heat detections, spread across 2 municipalities.
It is the 22th largest in Minas Gerais since 2016 (of 227 with a page). Number 116 in Brazil in 2025, of 714.
- Burnt area
- 10,428ha
- GWIS perimeter (Copernicus)
- Duration
- 11days
- 30 Sept 2025 – 10 Oct 2025
- Municipalities hit
- 2
- municipalities
- Started on
- 30 Sept
- 2025
- Heat detections
- 295
- in a single hotspot: 117 MW
- Danger at start
- 34
- High · FWI index
- Energy released
- 2.6GW
- 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 4 days without rain (1 mm or more) when it started. Rain came after the fire: 2.3 mm on 18 Oct.
This area had burned before
No earlier perimeters overlap this fire since 2016, when the satellite record begins.
What happened to each town
-
10,445 ha reached on 1 Oct3.2 %
-
Três Marias 28,895 inhabitants47 ha reached on 8 Oct0.0 %
Burnt area inside each municipality, from crossing the GWIS 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.
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) |
|---|---|---|---|---|---|
| 30 Sept | 32.8 °C | 22 % | 26 km/h | 0.0 mm | High 34 |
| 1 Oct | 31.8 °C | 23 % | 25 km/h | 0.0 mm | High 33 |
| 2 Oct | 30.8 °C | 25 % | 31 km/h | 0.0 mm | High 34 |
| 3 Oct | 29.7 °C | 26 % | 36 km/h | 0.0 mm | High 36 |
| 4 Oct | 30.3 °C | 29 % | 41 km/h | 0.0 mm | Very high 39 |
| 5 Oct | 31.3 °C | 27 % | 32 km/h | 0.0 mm | High 35 |
| 6 Oct | 32.7 °C | 30 % | 30 km/h | 0.0 mm | High 34 |
| 7 Oct | 35.5 °C | 20 % | 31 km/h | 0.0 mm | High 37 |
| 8 Oct | 33.9 °C | 26 % | 31 km/h | 0.0 mm | Very high 40 |
| 9 Oct | 31.2 °C | 38 % | 40 km/h | 0.1 mm | High 35 |
| 10 Oct | 31.1 °C | 33 % | 34 km/h | 0.0 mm | High 32 |
| 11 Oct after | 31.2 °C | 33 % | 29 km/h | 0.0 mm | High 32 |
| 12 Oct after | 33.5 °C | 27 % | 35 km/h | 0.0 mm | High 35 |
| 13 Oct after | 31.5 °C | 35 % | 25 km/h | 0.0 mm | High 29 |
| 14 Oct after | 28.9 °C | 44 % | 19 km/h | 0.5 mm | High 25 |
| 15 Oct after | 33.5 °C | 33 % | 24 km/h | 0.2 mm | High 29 |
| 16 Oct after | 33.4 °C | 32 % | 24 km/h | 0.0 mm | High 29 |
| 17 Oct after | 33.1 °C | 33 % | 27 km/h | 0.1 mm | High 31 |
| 18 Oct after | 34.7 °C | 22 % | 38 km/h | 2.3 mm | High 33 |
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 9 October 2025 the air beside the fire reached 18 µg/m³ of PM2.5, but no daily average passed the WHO 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 · 295Every 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 Lassance fire last?
- GWIS (Copernicus) dates it between 30 September 2025 and 10 October 2025: 11 days between the first and last heat detection of the perimeter.
- How much area did it burn?
- The perimeter GWIS (Copernicus) rebuilt from heat detections is 10,428 hectares (104.3 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire entered 2 municipalities: Lassance (10,445 ha, 3.2 %); Três Marias (47 ha, 0.0 %).
- What was the weather like?
- During the fire the temperature reached 35.5 °C, humidity dropped to 20 % and gusts hit 41 km/h. The fire danger index (FWI) reached 40, class Very high.
- Where does this data come from?
- From the GWIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Brazil (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: 193
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 comes from the Copernicus Global Wildfire Information System (GWIS), which rebuilds it from MODIS and VIIRS heat detections and publishes it under CC BY 4.0. It is not measured on imagery as in Europe, so it is an estimate. 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 ADM2 (Creative Commons Attribution 3.0 Intergovernmental Organisations (CC BY 3.0 IGO)). The area per municipality is computed by WorldFires by crossing the perimeter with those boundaries, so it may differ from each country’s official figure.