Skip to content
worldfires
BR · Brazil · –

Altamira fire, 29 September 2025 Altamira

Out · last detection 7 Oct 2025, 17:12 UTC

The fire started on 29 September 2025 in Altamira, Brazil, and satellites saw it burning for 9 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 3,529 hectares from heat detections, spread across a single municipality.

It is the 741th largest in Pará since 2016 (of 957 with a page). Number 425 in Brazil in 2025, of 526.

Burnt area
3,529ha
GWIS perimeter (Copernicus)
Duration
9days
29 Sept 2025 – 7 Oct 2025
Municipalities hit
1
municipalities
Started on
29 Sept
2025
Heat detections
217
in a single hotspot: 65 MW
Danger at start
13
Moderate · FWI index
Average daily power
308MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 29 Sept7 Oct
7 Oct 2025

How it evolved, day by day

30 Sept 2025 · 37 MW · 15 1 Oct 2025 · 9 MW · 2 2 Oct 2025 · 56 MW · 8 3 Oct 2025 · 43 MW · 4 4 Oct 2025 · 1,697 MW · 84 5 Oct 2025 · 464 MW · 57 6 Oct 2025 · 146 MW · 37 7 Oct 2025 · 15 MW · 10
30 Sept 2 Oct 4 Oct 6 Oct

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

The weather it burned in

36°high
39km/h · peak gust
27%lowest humidity

It had gone 2 days without rain (1 mm or more) when it started. Rain came after the fire: 5.0 mm on 8 Oct.

This area had burned before

44% of the perimeter overlaps earlier fires recorded since 2016: 567 ha in 2020, 1,000 ha in 2023.

How big is it?

10 km
It burned the equivalent of 2.2% of the area of London (35 km² against 1,583 km²).

London boundary: geoBoundaries · Office for National Statistics (Open Government Licence v3.0).

This compares size, not location: both shapes are at the same scale, north up, centred on each other.

What happened to each town

  1. Altamira 126,279 inhabitants where it started
    3,577 ha reached on 30 Sept
    0.0 %

Burnt area inside each municipality, from crossing the GWIS perimeter with administrative boundaries. The distance runs from the point marking the centre of each area to the nearest fire: staying a kilometre away does not mean it reached the houses.

People and buildings inside the perimeter

GHSL 2025
Built-up area< 0.1 ha
Residents< 20

Inside the perimeter there was no noticeable built-up land and almost nobody lived there (GHSL 2025, satellite-based estimate).

This is an estimate on 100 m cells, made from satellite imagery and census data: it does not mean that homes burned or that anyone was harmed. The perimeter also contains land that never burned. The GHSL 2025 epoch is a projection made from 2020 and earlier data.

Source: Global Human Settlement Layer (GHS-BUILT-S and GHS-POP R2023A), European Commission Joint Research Centre (JRC), © European Union, CC BY 4.0. Sum inside the perimeter computed by WorldFires. human-settlement.emergency.copernicus.eu

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)
29 Sept 34.2 °C 35 % 35 km/h 0.0 mm Moderate 13
30 Sept 35.1 °C 30 % 28 km/h 0.0 mm Moderate 15
1 Oct 34.4 °C 38 % 28 km/h 0.0 mm Moderate 15
2 Oct 33.7 °C 38 % 32 km/h 0.0 mm Moderate 16
3 Oct 34.6 °C 37 % 25 km/h 0.0 mm Moderate 16
4 Oct 34.7 °C 36 % 37 km/h 0.0 mm Moderate 19
5 Oct 35.7 °C 27 % 39 km/h 0.0 mm High 24
6 Oct 34.3 °C 34 % 26 km/h 0.1 mm High 21
7 Oct 35.5 °C 31 % 23 km/h 0.0 mm High 22
8 Oct after 32.2 °C 45 % 27 km/h 5.0 mm Very low 3

Its twins: fires that started in the same weather

It started with an FWI of 12.7, a minimum humidity of 35% and 2 days without rain. Fires in the area that started in weather like this since 2016: 9.

FWI at the start 12.7
Minimum humidity 35 %
Days without rain 2
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Novo Progresso fire, August 2018
3,090 ha 15 days FWI 13.9 Min. humidity 35 % 237 km away, in 2018

First rain (1 mm or more) after it ended: 3.1 mm on 7 Sept.

What happened to them

Fires in the area that started in similar weather: 9. With fewer than 15 we give no figures: they would be more noise than signal.

This is a bank of analogues: it shows what usually happens, not what will happen. With fewer than 15 twins we give no figures. How we calculate it

How it ended

5.0 mmfirst rain
8 Octthe day after it ended
39km/h · max. gust

It was considered over on 7 Oct, and on 8 Oct 5.0 mm fell. We do not know whether the rain or the firefighters put it out.

Weather on this page: Open-Meteo.com (CC BY 4.0) · Copernicus Climate Change Service (ERA5)

How a twin is chosen

  • Same area: fires that have already ended, less than 250 km from this one, since 2016.
  • Same start: we compare the FWI on the first day, the minimum humidity that day and the run of days without rain before it. The slider sets how much they may differ.
  • Only pages with final weather data (ERA5 reanalysis) calculated in the same way as this fire’s; agricultural and grass burns and pages with data under review are left out.
  • Fires burning at the same time as this one (a week before or after) are left out: they share the same spell of weather and do not count as a precedent.
  • They are sorted by similarity, and the outlines of the first five are drawn.

How we calculate it

Before and after, from space

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

Before · 22 Sept 2025
After · 14 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 4 October 2025 the air beside the fire reached 72 µg/m³ of PM2.5. That day averaged 39: 2.6 times the WHO daily guideline (15).

PM2.5 peak72 µg/m³
Days over the guideline9 days
PM1074 µg/m³
Optical depth0.89
27 Sept30 Sept3 Oct6 Oct9 Oct
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 · 217Every 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 Altamira fire last?
GWIS (Copernicus) dates it between 29 September 2025 and 7 October 2025: 9 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 3,529 hectares (35.3 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire only entered Altamira (3,577 ha, 0.0 %).
What was the weather like?
During the fire the temperature reached 35.7 °C, humidity dropped to 27 % and gusts hit 39 km/h. The fire danger index (FWI) reached 24, class 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 · Emergency number and official warnings

Satellite cross-check

History of this page Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.

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.

How we know this
  • Perimeter: GWIS (Copernicus), rebuilt from heat detections rather than mapped on imagery.
  • Dates from the perimeter: the VIIRS detections inside it did not change them. 217 Suomi-NPP VIIRS detections on those dates.
  • We have not matched this page with any official record.
  • Weather: Copernicus ERA5 reanalysis at the fire location, in cells of about 25 km.
  • Built-up area and population come from the JRC Global Human Settlement Layer (epoch 2025, 100 m cells), summed inside the perimeter: an estimate of what was there, not a damage count.

How we build fire pages: methodology

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.