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Balsas fire, June 2023 Balsas

Out · last detection 21 Jun 2023, 16:01 UTC

The fire started on 11 June 2023 in Balsas, Brazil, and satellites saw it burning for 11 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 4,105 hectares from heat detections, spread across a single municipality.

It is the 332th largest in Maranhão since 2016 (of 607 with a page). Number 242 in Brazil in 2023, of 431.

Compare with…

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

Burnt area
4,105ha
GWIS perimeter (Copernicus)
Duration
11days
11 Jun 2023 – 21 Jun 2023
Municipalities hit
1
municipalities
Started on
11 Jun
2023
Heat detections
122
in a single hotspot: 320 MW
Danger at start
28
High · FWI index
Average daily power
141MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 11 Jun21 Jun
21 Jun 2023

How it evolved, day by day

11 Jun 2023 · 250 MW · 17 12 Jun 2023 · 483 MW · 8 13 Jun 2023 · 141 MW · 23 14 Jun 2023 · 69 MW · 14 15 Jun 2023 · 306 MW · 17 16 Jun 2023 · 112 MW · 12 17 Jun 2023 · 93 MW · 12 18 Jun 2023 · 65 MW · 14 19 Jun 2023 · 18 MW · 3 20 Jun 2023 · 6 MW · 1 21 Jun 2023 · 3 MW · 1
11 Jun 12 Jun 13 Jun 15 Jun 17 Jun 19 Jun 21 Jun

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

The weather it burned in

33°high
42km/h · peak gust
34%lowest humidity

It had gone 26 days without rain (1 mm or more) when it started.

This area had burned before

60% of the perimeter overlaps earlier fires recorded since 2016: 1,926 ha in 2016, 1,054 ha in 2019, 7 ha in 2022. Part of it burned more than once, so the yearly figures add up to more than the 2,457 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 2.6% of the area of London (41 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
    4,135 ha reached on 11 Jun
    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 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)
11 Jun 32.6 °C 38 % 33 km/h 0.0 mm High 28
12 Jun 32.8 °C 39 % 33 km/h 0.0 mm High 29
13 Jun 33.0 °C 36 % 34 km/h 0.0 mm High 29
14 Jun 31.8 °C 40 % 37 km/h 0.0 mm High 31
15 Jun 32.6 °C 36 % 35 km/h 0.0 mm High 30
16 Jun 32.8 °C 40 % 33 km/h 0.0 mm High 30
17 Jun 32.7 °C 39 % 30 km/h 0.0 mm High 29
18 Jun 32.6 °C 37 % 31 km/h 0.0 mm High 30
19 Jun 33.1 °C 34 % 34 km/h 0.0 mm High 31
20 Jun 31.9 °C 40 % 42 km/h 0.0 mm High 36
21 Jun 31.2 °C 42 % 42 km/h 0.0 mm High 34
22 Jun after 31.6 °C 39 % 43 km/h 0.0 mm High 35
23 Jun after 31.2 °C 34 % 39 km/h 0.0 mm High 35
24 Jun after 31.7 °C 35 % 37 km/h 0.0 mm High 33
25 Jun after 31.7 °C 35 % 37 km/h 0.0 mm High 34
26 Jun after 31.6 °C 30 % 39 km/h 0.0 mm High 36
27 Jun after 31.2 °C 36 % 38 km/h 0.0 mm High 36
28 Jun after 32.6 °C 33 % 37 km/h 0.0 mm High 35
29 Jun after 32.2 °C 33 % 34 km/h 0.0 mm High 34
30 Jun after 32.4 °C 35 % 37 km/h 0.0 mm High 36
1 Jul after 32.6 °C 33 % 39 km/h 0.0 mm High 38

Before and after, from space

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

Before · 4 Jun 2023
After · 28 Jun 2023

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 17 June 2023 the air beside the fire reached 23 µg/m³ of PM2.5, but no daily average passed the WHO guideline (15).

PM2.5 peak23 µg/m³
Days over the guideline0 days
PM1032 µg/m³
Optical depth0.21
9101112131415161718192021222324
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 · 122Every 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 June 2023 and 21 June 2023: 11 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 4,105 hectares (41.0 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire only entered Balsas (4,135 ha, 0.3 %).
What was the weather like?
During the fire the temperature reached 33.1 °C, humidity dropped to 34 % and gusts hit 42 km/h. The fire danger index (FWI) reached 36, 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.

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. 122 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.