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Formosa fire, 12 September 2025 Formosa

Out · last detection 17 Sept 2025, 04:12 UTC

The fire started on 12 September 2025 in Formosa, Brazil, and satellites saw it burning for 6 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 4,394 hectares from heat detections, spread across a single municipality.

It is the 327th largest in Goiás since 2016 (of 548 with a page). Number 426 in Brazil in 2025, of 714.

Burnt area
4,394ha
GWIS perimeter (Copernicus)
Duration
6days
12 Sept 2025 – 17 Sept 2025
Municipalities hit
1
municipalities
Started on
12 Sept
2025
Heat detections
101
in a single hotspot: 81 MW
Danger at start
43
Very high · FWI index
Energy released
826MW
sum of detected power

Where it burned

17 Sept 2025
HOTSPOTS BY DAY 12 Sept17 Sept

How it evolved, day by day

121314151617

Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.

The weather it burned in

35°high
39km/h · peak gust
14%lowest humidity

It had gone more than two months without rain (1 mm or more) when it started. Rain came after the fire: 6.4 mm on 22 Sept.

This area had burned before

63% of the perimeter overlaps earlier fires recorded since 2016: 1,002 ha in 2016, 1,842 ha in 2021.

What happened to each town

  1. Formosa 115,901 inhabitants where it started
    4,423 ha reached on 12 Sept
    0.8 %

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)
12 Sept 35.2 °C 14 % 30 km/h 0.0 mm Very high 43
13 Sept 33.1 °C 19 % 39 km/h 0.0 mm Very high 49
14 Sept 32.6 °C 22 % 35 km/h 0.0 mm Very high 45
15 Sept 31.8 °C 26 % 35 km/h 0.0 mm Very high 42
16 Sept 32.6 °C 24 % 32 km/h 0.0 mm Very high 41
17 Sept 32.3 °C 24 % 28 km/h 0.1 mm Very high 41
18 Sept after 33.8 °C 24 % 28 km/h 0.1 mm Very high 42
19 Sept after 29.3 °C 35 % 36 km/h 0.1 mm High 38
20 Sept after 30.3 °C 30 % 31 km/h 0.9 mm High 28
21 Sept after 33.2 °C 23 % 37 km/h 0.0 mm Very high 38
22 Sept after 30.7 °C 43 % 41 km/h 6.4 mm Low 8

Before and after, from space

Drag the line to compare the same ground before the fire and after it.

Before · 5 Sept 2025
After · 24 Sept 2025

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 · Copernicus

On 12 September 2025 the air beside the fire reached 33 µg/m³ of PM2.5. That day averaged 21: 1.4 times the WHO daily guideline (15).

PM2.5 peak33 µg/m³
Days over the guideline1 day
PM1034 µg/m³
Optical depth0.59
1011121314151617181920
Good Fair Moderate Poor Very poor Extremely poor

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 · 101Every satellite heat detection, one by one, with time, satellite, power and coordinates.
⬇ Download CSV Times in UTC. Each detection is a 375 m pixel: a large fire yields hundreds per pass.
Date and timeSatelliteFRP (MW)LatLon

Other fires nearby

All fires in Brazil ›

Frequently asked questions

How long did the Formosa fire last?
GWIS (Copernicus) dates it between 12 September 2025 and 17 September 2025: 6 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 4,394 hectares (43.9 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire only entered Formosa (4,423 ha, 0.8 %).
What was the weather like?
During the fire the temperature reached 35.2 °C, humidity dropped to 14 % and gusts hit 39 km/h. The fire danger index (FWI) reached 49, 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
What do you think is wrong?

We will only use your email to reply about this report. Privacy. This is not an emergency service: if there is a fire now, call 193.

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.