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Caxias fire, August 2023 Caxias, Aldeias Altas

Out · last detection 14 Aug 2023, 15:49 UTC

The fire started on 7 August 2023 in Caxias, Brazil, and satellites saw it burning for 9 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 3,724 hectares from heat detections, spread across 2 municipalities.

It is the 400th largest in Maranhão since 2016 (of 607 with a page). Number 302 in Brazil in 2023, of 431.

Compare with…

Suggestions: Caxias · 2016Aldeias Altas · 2021Aldeias Altas · 2022Aldeias Altas · 2021

Burnt area
3,724ha
GWIS perimeter (Copernicus)
Duration
9days
7 Aug 2023 – 15 Aug 2023
Municipalities hit
2
municipalities
Started on
7 Aug
2023
Heat detections
193
in a single hotspot: 172 MW
Danger at start
34
High · FWI index
Average daily power
449MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 7 Aug15 Aug
14 Aug 2023

How it evolved, day by day

7 Aug 2023 · 25 MW · 2 9 Aug 2023 · 315 MW · 5 10 Aug 2023 · 1,207 MW · 81 11 Aug 2023 · 724 MW · 38 12 Aug 2023 · 168 MW · 15 13 Aug 2023 · 649 MW · 44 14 Aug 2023 · 54 MW · 8
7 Aug 9 Aug 10 Aug 11 Aug 12 Aug 13 Aug 14 Aug

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

The weather it burned in

36°high
46km/h · peak gust
32%lowest humidity

It had gone 29 days without rain (1 mm or more) when it started.

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 2.4% of the area of London (37 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. Caxias 156,973 inhabitants where it started
    3,702 ha reached on 7 Aug
    0.7 %
  2. Aldeias Altas 23,286 inhabitants
    46 ha
    0.0 %

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 area0.88 ha
Residents≈ 150

Inside the perimeter there were about 0.88 hectares of built-up land and about 150 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)

Day High Min. humidity Peak gust Rain Danger (FWI)
7 Aug 34.2 °C 39 % 40 km/h 0.1 mm High 34
8 Aug 34.3 °C 40 % 41 km/h 0.0 mm High 35
9 Aug 34.1 °C 39 % 41 km/h 0.1 mm High 34
10 Aug 34.1 °C 35 % 36 km/h 0.0 mm High 33
11 Aug 33.9 °C 35 % 36 km/h 0.0 mm High 33
12 Aug 33.3 °C 38 % 31 km/h 0.0 mm High 32
13 Aug 34.3 °C 33 % 31 km/h 0.1 mm High 31
14 Aug 34.6 °C 32 % 32 km/h 0.0 mm High 32
15 Aug 34.0 °C 34 % 39 km/h 0.0 mm High 35
16 Aug after 34.1 °C 34 % 42 km/h 0.0 mm High 38
17 Aug after 33.8 °C 35 % 43 km/h 0.0 mm Very high 40
18 Aug after 34.5 °C 34 % 37 km/h 0.0 mm High 35
19 Aug after 34.4 °C 38 % 34 km/h 0.0 mm High 34
20 Aug after 35.3 °C 36 % 40 km/h 0.0 mm High 36
21 Aug after 35.7 °C 35 % 46 km/h 0.0 mm High 38
22 Aug after 34.1 °C 39 % 34 km/h 0.0 mm High 36
23 Aug after 35.0 °C 29 % 44 km/h 0.0 mm Very high 40
24 Aug after 35.4 °C 35 % 31 km/h 0.0 mm Very high 40
25 Aug after 35.1 °C 39 % 30 km/h 0.0 mm High 37
26 Aug after 35.1 °C 39 % 29 km/h 0.0 mm High 37
27 Aug after 34.8 °C 40 % 30 km/h 0.1 mm High 35
28 Aug after 33.0 °C 47 % 30 km/h 0.2 mm High 30
29 Aug after 35.1 °C 38 % 30 km/h 0.0 mm High 30
30 Aug after 34.4 °C 42 % 31 km/h 0.2 mm High 31
31 Aug after 34.1 °C 41 % 24 km/h 0.0 mm High 32

Before and after, from space

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

Before · 31 Jul 2023
After · 22 Aug 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 12 August 2023 the air beside the fire reached 271 µg/m³ of PM2.5. That day averaged 137: 9.1 times the WHO daily guideline (15).

PM2.5 peak271 µg/m³
Days over the guideline5 days
PM10386 µg/m³
Optical depth1.55
789101112131415161718
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 · 193Every 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 Caxias fire last?
According to the heat detections seen by satellite inside the perimeter, it burned from 7 August 2023 to 15 August 2023 (9 days). The perimeter dates it from 9 August 2023 to 15 August 2023.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 3,724 hectares (37.2 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 2 municipalities: Caxias (3,702 ha, 0.7 %); Aldeias Altas (46 ha, 0.0 %).
What was the weather like?
During the fire the temperature reached 35.7 °C, humidity dropped to 32 % and gusts hit 46 km/h. The fire danger index (FWI) reached 40, 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 · 1 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.
  1. Start date: 9 August 2023 → 7 August 2023.

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 adjusted with the VIIRS detections inside the perimeter, which said 9 August 2023 to 15 August 2023. 193 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.