How long did the Balsas fire last?

GWIS (Copernicus) dates it between 29 August 2017 and 5 September 2017: 8 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 5,674 hectares (56.7 km²). It is an estimate: official national figures may differ.

Which municipalities burned?

The fire only entered Balsas (5,704 ha, 0.4 %).

What was the weather like?

During the fire the temperature reached 39.5 °C, humidity dropped to 15 % and gusts hit 50 km/h. The fire danger index (FWI) reached 58, 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 · 2017-08-29 → 2017-09-05

Balsas fire, 29 August 2017 Balsas

Out · last detection 6 Sept 2017, 16:38 UTC

The fire started on 29 August 2017 in Balsas, Brazil, and satellites saw it burning for 8 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 5,674 hectares from heat detections, spread across a single municipality.

It is the 182th largest in Maranhão since 2016 (of 607 with a page). Number 385 in Brazil in 2017, of 994.

Compare with…

Suggestions: Tasso Fragoso · 2017 Balsas · 2017 Balsas · 2025 Balsas · 2026

Burnt area: 5,674ha; GWIS perimeter (Copernicus)
Duration: 8days; 29 Aug 2017 – 5 Sept 2017
Municipalities hit: 1; municipalities
Started on: 29 Aug; 2017
Heat detections: 174; in a single hotspot: 64 MW
Danger at start: 46; Very high · FWI index
Average daily power: 183MW; detected power per day, on average

HOTSPOTS BY DAY 29 Aug5 Sept

Play back 6 Sept 2017

How it evolved, day by day

29 Aug 31 Aug 2 Sept 4 Sept 6 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

40°high

50km/h · peak gust

15%lowest humidity

It had gone more than two months without rain (1 mm or more) when it started.

This area had burned before

10% of the perimeter overlaps earlier fires recorded since 2016: 572 ha in 2016.

How big is it?

It burned the equivalent of 3.6% of the area of London (57 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

5,704 ha reached on 29 Aug

0.4 %

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.

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	Danger (FWI)
29 Aug	38.2 °C	21 %	38 km/h	Very high 46
30 Aug	38.8 °C	16 %	39 km/h	Extreme 50
31 Aug	39.5 °C	15 %	36 km/h	Extreme 50
1 Sept	38.2 °C	21 %	38 km/h	Extreme 53
2 Sept	36.4 °C	22 %	42 km/h	Extreme 53
3 Sept	35.8 °C	23 %	49 km/h	Extreme 56
4 Sept	35.4 °C	22 %	50 km/h	Extreme 58
5 Sept	36.5 °C	23 %	48 km/h	Extreme 57
6 Sept after	37.1 °C	25 %	42 km/h	Extreme 52
7 Sept after	37.0 °C	30 %	42 km/h	Very high 47
8 Sept after	38.6 °C	19 %	40 km/h	Very high 48
9 Sept after	37.9 °C	22 %	42 km/h	Extreme 50
10 Sept after	37.6 °C	23 %	46 km/h	Extreme 53
11 Sept after	37.4 °C	21 %	45 km/h	Extreme 53
12 Sept after	37.5 °C	22 %	48 km/h	Extreme 55
13 Sept after	37.2 °C	20 %	44 km/h	Extreme 52
14 Sept after	38.0 °C	20 %	44 km/h	Extreme 54
15 Sept after	37.5 °C	21 %	46 km/h	Extreme 55
16 Sept after	36.0 °C	23 %	46 km/h	Extreme 54

Before and after, from space

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

↔

Before · 22 Aug 2017

After · 12 Sept 2017

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.

Detections table · 174Every 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 29 August 2017 and 5 September 2017: 8 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 5,674 hectares (56.7 km²). It is an estimate: official national figures may differ.
Which municipalities burned?: The fire only entered Balsas (5,704 ha, 0.4 %).
What was the weather like?: During the fire the temperature reached 39.5 °C, humidity dropped to 15 % and gusts hit 50 km/h. The fire danger index (FWI) reached 58, 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

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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 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. 174 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.

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