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Amarante fire, September 2025 Francisco Ayres, Floriano, Amarante

Out · last detection 16 Oct 2025, 16:04 UTC

The fire started on 24 September 2025 in Amarante, Brazil, and satellites saw it burning for 22 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 14,770 hectares from heat detections, spread across 3 municipalities.

It is the 54th largest in Piaui since 2016 (of 803 with a page). Number 63 in Brazil in 2025, of 714.

Burnt area
14,770ha
GWIS perimeter (Copernicus)
Duration
22days
24 Sept 2025 – 15 Oct 2025
Municipalities hit
3
municipalities
Started on
24 Sept
2025
Heat detections
647
in a single hotspot: 98 MW
Danger at start
45
Very high · FWI index
Energy released
4.7GW
sum of detected power

Where it burned

16 Oct 2025
HOTSPOTS BY DAY 24 Sept15 Oct

How it evolved, day by day

252627282930123456789101112131516

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

The weather it burned in

38°high
52km/h · peak gust
17%lowest humidity

It had gone more than two months without rain (1 mm or more) when it started. Rain came after the fire: 3.1 mm on 21 Oct.

This area had burned before

93% of the perimeter overlaps earlier fires recorded since 2016: 812 ha in 2018, 10,958 ha in 2019, 10,704 ha in 2021, 596 ha in 2022, 7,151 ha in 2023, 269 ha in 2024. Part of it burned more than once, so the yearly figures add up to more than the 13,705 ha that had burned before.

What happened to each town

  1. Francisco Ayres 4,412 inhabitants
    9,645 ha reached on 25 Sept
    15 %
  2. Floriano 62,036 inhabitants
    4,601 ha reached on 5 Oct
    1.3 %
  3. Amarante 17,234 inhabitants where it started
    618 ha reached on 22 Sept
    0.5 %

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)
22 Sept 36.7 °C 29 % 34 km/h 0.0 mm Very high 45
23 Sept 38.1 °C 25 % 36 km/h 0.0 mm Very high 45
24 Sept 37.4 °C 20 % 42 km/h 0.0 mm Very high 49
25 Sept 36.5 °C 19 % 51 km/h 0.0 mm Extreme 57
26 Sept 36.4 °C 23 % 48 km/h 0.0 mm Extreme 56
27 Sept 36.3 °C 22 % 50 km/h 0.0 mm Extreme 57
28 Sept 35.9 °C 23 % 50 km/h 0.0 mm Extreme 58
29 Sept 35.8 °C 26 % 46 km/h 0.0 mm Extreme 54
30 Sept 36.4 °C 23 % 46 km/h 0.0 mm Extreme 54
1 Oct 36.0 °C 27 % 45 km/h 0.0 mm Extreme 52
2 Oct 37.0 °C 24 % 44 km/h 0.0 mm Extreme 53
3 Oct 36.2 °C 20 % 47 km/h 0.0 mm Extreme 54
4 Oct 36.6 °C 17 % 52 km/h 0.0 mm Extreme 59
5 Oct 36.6 °C 23 % 47 km/h 0.0 mm Extreme 56
6 Oct 36.9 °C 25 % 45 km/h 0.0 mm Extreme 56
7 Oct 37.3 °C 27 % 36 km/h 0.0 mm Very high 48
8 Oct 37.8 °C 23 % 38 km/h 0.0 mm Very high 50
9 Oct 37.3 °C 24 % 40 km/h 0.0 mm Very high 50
10 Oct 37.4 °C 24 % 46 km/h 0.0 mm Extreme 55
11 Oct 36.7 °C 24 % 37 km/h 0.0 mm Very high 49
12 Oct 37.9 °C 22 % 35 km/h 0.0 mm Very high 48
13 Oct 37.2 °C 27 % 32 km/h 0.0 mm Very high 46
14 Oct 38.1 °C 20 % 34 km/h 0.0 mm Very high 47
15 Oct 38.1 °C 19 % 38 km/h 0.0 mm Very high 49
16 Oct after 37.5 °C 17 % 46 km/h 0.0 mm Extreme 58
17 Oct after 37.5 °C 23 % 42 km/h 0.0 mm Extreme 54
18 Oct after 37.3 °C 28 % 32 km/h 0.0 mm Very high 44
19 Oct after 37.9 °C 29 % 31 km/h 0.0 mm Very high 42
20 Oct after 33.4 °C 44 % 28 km/h 0.2 mm High 35
21 Oct after 31.2 °C 45 % 52 km/h 3.1 mm Moderate 17

Before and after, from space

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

Before · 17 Sept 2025
After · 22 Oct 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 18 October 2025 the air beside the fire reached 33 µg/m³ of PM2.5. That day averaged 20: 1.3 times the WHO daily guideline (15).

PM2.5 peak33 µg/m³
Days over the guideline2 days
PM1034 µg/m³
Optical depth0.41
222324252627282930123456789101112131415161718
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 · 647Every 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 Amarante fire last?
GWIS (Copernicus) dates it between 24 September 2025 and 15 October 2025: 22 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 14,770 hectares (147.7 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 3 municipalities: Francisco Ayres (9,645 ha, 15 %); Floriano (4,601 ha, 1.3 %); Amarante (618 ha, 0.5 %).
What was the weather like?
During the fire the temperature reached 38.1 °C, humidity dropped to 17 % and gusts hit 52 km/h. The fire danger index (FWI) reached 59, class Extreme.
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.