How long did the Balsas fire last?

GWIS (Copernicus) dates it between 30 August 2026 and 3 September 2026: 5 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 3,405 hectares (34.0 km²). It is an estimate: official national figures may differ.

Which municipalities burned?

The fire only entered Balsas (3,431 ha, 0.3 %).

What was the weather like?

During the fire the temperature reached 37.7 °C, humidity dropped to 16 % and gusts hit 44 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.

BR · Brazil · 2026-08-30 → 2026-09-03

Balsas fire, 30 August 2026 Balsas

Out · last detection 3 Sept 2026, 04:38 UTC

The fire started on 30 August 2026 in Balsas, Brazil, and satellites saw it burning for 5 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 3,405 hectares from heat detections, spread across a single municipality.

It is the 475th largest in Maranhão since 2016 (of 608 with a page). Number 645 in Brazil in 2026, of 769.

Compare with…

Suggestions: Balsas · 2023 Balsas · 2025 Balsas · 2024 Balsas · 2025

Burnt area: 3,405ha; GWIS perimeter (Copernicus)
Duration: 5days; 30 Aug 2026 – 3 Sept 2026
Municipalities hit: 1; municipalities
Started on: 30 Aug; 2026
Heat detections: 59; in a single hotspot: 109 MW
Danger at start: 53; Extreme · FWI index
Average daily power: 248MW; detected power per day, on average

HOTSPOTS BY DAY 30 Aug3 Sept

Play back 3 Sept 2026

How it evolved, day by day

30 Aug 31 Aug 1 Sept 2 Sept 3 Sept

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

44km/h · peak gust

16%lowest humidity

It had gone 45 days without rain (1 mm or more) when it started.

This area had burned before

66% of the perimeter overlaps earlier fires recorded since 2016: 1,413 ha in 2017, 106 ha in 2020, 1,208 ha in 2023, 210 ha in 2025. Part of it burned more than once, so the yearly figures add up to more than the 2,261 ha that had burned before.

1,197 ha Balsas fire, September 2023 8,691 ha in total; the hectares shown are those it shares with this fire

How big is it?

It burned the equivalent of 2.2% of the area of London (34 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

Balsas 101,767 inhabitants where it started

3,431 ha reached on 30 Aug

0.3 %

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 area0.14 ha

Residents< 20

Inside the perimeter there were about 0.14 hectares of 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)
30 Aug	37.3 °C	19 %	41 km/h	0.0 mm	Extreme 53
31 Aug	37.7 °C	16 %	34 km/h	0.0 mm	Very high 49
1 Sept	37.1 °C	22 %	36 km/h	0.0 mm	Extreme 50
2 Sept	35.8 °C	32 %	29 km/h	0.1 mm	Very high 40
3 Sept	35.1 °C	36 %	35 km/h	0.6 mm	High 34
4 Sept after	31.6 °C	45 %	40 km/h	4.6 mm	Low 10
5 Sept after	33.8 °C	37 %	21 km/h	0.0 mm	Moderate 20
6 Sept after	33.5 °C	42 %	19 km/h	1.6 mm	Moderate 12
7 Sept after	33.5 °C	39 %	20 km/h	0.0 mm	High 22
8 Sept after	34.7 °C	29 %	39 km/h	0.2 mm	High 35
9 Sept after	35.5 °C	20 %	42 km/h	0.0 mm	Very high 45
10 Sept after	34.8 °C	20 %	44 km/h	0.0 mm	Very high 46
11 Sept after	35.5 °C	23 %	47 km/h	0.0 mm	Very high 48
12 Sept after	36.0 °C	21 %	41 km/h	0.0 mm	Very high 45
13 Sept after	36.4 °C	23 %	34 km/h	0.0 mm	Very high 42
14 Sept after	36.5 °C	22 %	39 km/h	0.0 mm	Very high 45
15 Sept after	36.9 °C	19 %	41 km/h	0.0 mm	Very high 48
16 Sept after	38.5 °C	13 %	35 km/h	0.0 mm	Extreme 51
17 Sept after	37.5 °C	15 %	45 km/h	0.0 mm	Extreme 58
18 Sept after	35.8 °C	25 %	52 km/h	0.0 mm	Extreme 56
19 Sept after	36.0 °C	19 %	47 km/h	0.0 mm	Extreme 53
20 Sept after	34.3 °C	27 %	45 km/h	0.0 mm	Very high 48

Before and after, from space

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

↔

Before · 23 Aug 2026

After · 10 Sept 2026

Before After

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 2 September 2026 the air beside the fire reached 18 µg/m³ of PM2.5, but no daily average passed the WHO guideline (15).

PM2.5 peak18 µg/m³

Days over the guideline0 days

PM1020 µg/m³

Optical depth0.49

WHO 15

2829303112345678910111213

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 · 59Every 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 time	Satellite	FRP (MW)	Lat	Lon

Other fires nearby

All fires in Brazil ›

Frequently asked questions

How long did the Balsas fire last?: GWIS (Copernicus) dates it between 30 August 2026 and 3 September 2026: 5 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 3,405 hectares (34.0 km²). It is an estimate: official national figures may differ.
Which municipalities burned?: The fire only entered Balsas (3,431 ha, 0.3 %).
What was the weather like?: During the fire the temperature reached 37.7 °C, humidity dropped to 16 % and gusts hit 44 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.

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 ›

INPE · Programa Queimadas ↗
IBAMA · Prevfogo ↗

Satellite cross-check

NASA FIRMS ↗
GWIS · Copernicus ↗

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

No changes since 24 October 2026.

RSS Changes to this page

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.

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What do you think is wrong?

Dates or duration Place or towns Burned area Name It was not a wildfire Same fire as another page Something else

What really happened?

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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. 59 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.

Where it burned