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Balsas fire, 11 October 2017 Balsas

Out · last detection 14 Oct 2017, 16:25 UTC

The fire started on 11 October 2017 in Balsas, Brazil, and satellites saw it burning for 4 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 3,954 hectares from heat detections, spread across a single municipality.

It is the 354th largest in Maranhão since 2016 (of 607 with a page). Number 657 in Brazil in 2017, of 994.

Compare with…

Suggestions: Balsas · 2022Balsas · 2025Balsas · 2025Balsas · 2021

Burnt area
3,954ha
GWIS perimeter (Copernicus)
Duration
4days
11 Oct 2017 – 14 Oct 2017
Municipalities hit
1
municipalities
Started on
11 Oct
2017
Heat detections
78
in a single hotspot: 112 MW
Danger at start
44
Very high · FWI index
Average daily power
439MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 11 Oct14 Oct
14 Oct 2017

How it evolved, day by day

11 Oct 2017 · 632 MW · 26 12 Oct 2017 · 592 MW · 26 13 Oct 2017 · 414 MW · 15 14 Oct 2017 · 117 MW · 8
11 Oct 12 Oct 13 Oct 14 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

38°high
53km/h · peak gust
26%lowest humidity

It had gone more than two months without rain (1 mm or more) when it started. Rain came after the fire: 16.2 mm on 30 Oct.

This area had burned before

No earlier perimeters overlap this fire since 2016, when the satellite record begins.

How big is it?

10 km
It burned the equivalent of 2.5% of the area of London (40 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. Balsas 101,767 inhabitants where it started
    3,983 ha reached on 11 Oct
    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 2015
Built-up area< 0.1 ha
Residents< 20

Inside the perimeter there was no noticeable built-up land and almost nobody lived there (GHSL 2015, 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.

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)
11 Oct 37.3 °C 27 % 38 km/h 0.0 mm Very high 44
12 Oct 37.6 °C 30 % 30 km/h 0.0 mm Very high 41
13 Oct 37.4 °C 29 % 30 km/h 0.0 mm Very high 39
14 Oct 38.5 °C 27 % 30 km/h 0.0 mm Very high 39
15 Oct after 37.8 °C 28 % 34 km/h 0.0 mm Very high 39
16 Oct after 33.7 °C 46 % 31 km/h 2.2 mm Moderate 13
17 Oct after 36.6 °C 27 % 41 km/h 0.0 mm Very high 38
18 Oct after 37.7 °C 26 % 41 km/h 0.0 mm Very high 42
19 Oct after 36.8 °C 32 % 53 km/h 0.0 mm Very high 44
20 Oct after 38.4 °C 26 % 49 km/h 0.0 mm Very high 44
21 Oct after 38.8 °C 24 % 48 km/h 0.0 mm Very high 48
22 Oct after 38.7 °C 19 % 45 km/h 0.0 mm Extreme 51
23 Oct after 39.1 °C 23 % 39 km/h 0.0 mm Very high 49
24 Oct after 38.9 °C 21 % 31 km/h 0.0 mm Very high 44
25 Oct after 38.2 °C 27 % 39 km/h 0.0 mm Very high 48
26 Oct after 37.7 °C 27 % 37 km/h 0.0 mm Very high 47
27 Oct after 35.0 °C 34 % 33 km/h 0.0 mm Very high 39
28 Oct after 32.7 °C 45 % 30 km/h 0.8 mm High 23
29 Oct after 38.1 °C 29 % 30 km/h 0.0 mm High 33
30 Oct after 29.3 °C 63 % 33 km/h 16.2 mm Very low 2

Before and after, from space

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

Before · 4 Oct 2017
After · 21 Oct 2017

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 · 78Every 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 Balsas fire last?
GWIS (Copernicus) dates it between 11 October 2017 and 14 October 2017: 4 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 3,954 hectares (39.5 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire only entered Balsas (3,983 ha, 0.3 %).
What was the weather like?
During the fire the temperature reached 38.5 °C, humidity dropped to 26 % and gusts hit 53 km/h. The fire danger index (FWI) reached 44, class Very 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.

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.

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. 78 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 2015, 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.