Skip to content
worldfires
BR · Brazil · –

Janaúba fire, September 2025 Janaúba

Out · last detection 11 Oct 2025, 15:55 UTC

The fire started on 30 September 2025 in Janaúba, Brazil, and satellites saw it burning for 12 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 4,248 hectares from heat detections, spread across a single municipality.

It is the 97th largest in Minas Gerais since 2016 (of 210 with a page). Number 342 in Brazil in 2025, of 526.

Burnt area
4,248ha
GWIS perimeter (Copernicus)
Duration
12days
30 Sept 2025 – 11 Oct 2025
Municipalities hit
1
municipalities
Started on
30 Sept
2025
Heat detections
177
in a single hotspot: 177 MW
Danger at start
49
Very high · FWI index
Average daily power
528MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 30 Sept11 Oct
11 Oct 2025

How it evolved, day by day

30 Sept 2025 · 2 MW · 2 1 Oct 2025 · 1,564 MW · 37 2 Oct 2025 · 1,723 MW · 65 3 Oct 2025 · 1,349 MW · 40 4 Oct 2025 · 17 MW · 4 5 Oct 2025 · 13 MW · 5 8 Oct 2025 · 113 MW · 4 9 Oct 2025 · 204 MW · 10 10 Oct 2025 · 279 MW · 8 11 Oct 2025 · 11 MW · 2
30 Sept 2 Oct 4 Oct 8 Oct 10 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

37°high
49km/h · peak gust
19%lowest humidity

It had gone more than two months without rain (1 mm or more) when it started. Rain came after the fire: 1.6 mm on 14 Oct.

This area had burned before

77% of the perimeter overlaps earlier fires recorded since 2016: 3,221 ha in 2020, 44 ha in 2023.

How big is it?

10 km
It burned the equivalent of 2.7% of the area of London (42 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. Janaúba 70,699 inhabitants where it started
    4,276 ha reached on 30 Sept
    2.0 %

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 area0.79 ha
Residents≈ 30

Inside the perimeter there were about 0.79 hectares of built-up land and about 30 residents (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)

Started with 60 days without rain: 55 % of the area in Brazil

Day High Min. humidity Peak gust Rain Danger (FWI)
30 Sept 33.3 °C 22 % 41 km/h 0.0 mm Very high 49
1 Oct 32.7 °C 20 % 41 km/h 0.0 mm Very high 50
2 Oct 31.5 °C 24 % 42 km/h 0.0 mm Very high 47
3 Oct 30.6 °C 27 % 48 km/h 0.0 mm Very high 48
4 Oct 29.3 °C 34 % 47 km/h 0.0 mm Very high 42
5 Oct 30.8 °C 35 % 46 km/h 0.2 mm Very high 40
6 Oct 35.0 °C 22 % 33 km/h 0.0 mm Very high 44
7 Oct 36.7 °C 19 % 32 km/h 0.0 mm Very high 46
8 Oct 35.1 °C 22 % 39 km/h 0.0 mm Very high 49
9 Oct 33.7 °C 23 % 49 km/h 0.0 mm Extreme 53
10 Oct 33.4 °C 23 % 48 km/h 0.0 mm Extreme 52
11 Oct 35.0 °C 20 % 38 km/h 0.0 mm Very high 49
12 Oct after 33.8 °C 26 % 34 km/h 0.0 mm Very high 46
13 Oct after 34.4 °C 28 % 27 km/h 0.0 mm Very high 41
14 Oct after 34.2 °C 31 % 35 km/h 1.6 mm High 25

Its twins: fires that started in the same weather

It started with an FWI of 49.0, a minimum humidity of 22% and more than two months without rain. Fires in the area that started in weather like this since 2016: 19.

FWI at the start 49.0
Minimum humidity 22 %
Days without rain 60+
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Cocos fire, September 2025
3,493 ha 8 days FWI 50.4 Min. humidity 20 % 229 km away, in 2025

First rain (1 mm or more) after it ended: none in the following ten days.

What happened to them

8 days
median duration
3,704 ha
median area
11 %
went past 10,000 ha
5.8 mm
rain at the end (median; 8 of 19 had it)

It burned an area similar to its twins (4,248 ha against a median of 3,704 ha) and lasted 12 days, against 8 days.

In 11 of 19, not even 1 mm fell in the ten days after the end: they went out without rain. In the rest, the first rainy day brought a median of 5.8 mm.

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

1.6 mmfirst rain
14 Oct3 days after it ended
49km/h · max. gust

It was considered over on 11 Oct, and on 14 Oct 1.6 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 8 of 19, with a median of 5.8 mm.

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 · 23 Sept 2025
After · 18 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 14 µg/m³ of PM2.5, but no daily average passed the WHO guideline (15).

PM2.5 peak14 µg/m³
Days over the guideline0 days
PM1015 µg/m³
Optical depth0.33
28 Sept1 Oct4 Oct7 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 · 177Every 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 Janaúba fire last?
According to the heat detections seen by satellite inside the perimeter, it burned from 30 September 2025 to 11 October 2025 (12 days). The perimeter dates it from 30 September 2025 to 5 October 2025.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 4,248 hectares (42.5 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire only entered Janaúba (4,276 ha, 2.0 %).
What was the weather like?
During the fire the temperature reached 36.7 °C, humidity dropped to 19 % and gusts hit 49 km/h. The fire danger index (FWI) reached 53, 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.
How did the fires that started in similar weather in this area end?
Fires less than 250 km away that started since 2016 with a similar FWI, humidity and dry spell: 19. Their median duration was 8 days and their median area 3,704 ha; 11 % went past 10,000 ha. In 11 of 19, not even 1 mm fell in the ten days after the end: they went out without rain. In the rest, the first rainy day brought a median of 5.8 mm.

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 · 1 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.
  1. Last day with fire: 5 October 2025 → 11 October 2025.

RSS Changes to this page With cross-checks and a citable version

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 adjusted with the VIIRS detections inside the perimeter, which said 30 September 2025 to 5 October 2025. 177 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.