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Oeiras fire, August 2024 Oeiras, Cajazeiras do Piauí

Out · last detection 30 Aug 2024, 03:48 UTC

The fire started on 21 August 2024 in Oeiras, Brazil, and satellites saw it burning for 10 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 5,121 hectares from heat detections, spread across 2 municipalities.

It is the 329th largest in Piaui since 2016 (of 804 with a page). Number 658 in Brazil in 2024, of 1301.

Compare with…
Burnt area
5,121ha
GWIS perimeter (Copernicus)
Duration
10days
21 Aug 2024 – 30 Aug 2024
Municipalities hit
2
municipalities
Started on
21 Aug
2024
Heat detections
188
in a single hotspot: 99 MW
Danger at start
49
Very high · FWI index
Average daily power
132MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 21 Aug30 Aug
30 Aug 2024

How it evolved, day by day

21 Aug 2024 · 22 MW · 3 22 Aug 2024 · 23 MW · 8 23 Aug 2024 · 118 MW · 20 24 Aug 2024 · 57 MW · 23 25 Aug 2024 · 125 MW · 11 26 Aug 2024 · 144 MW · 18 27 Aug 2024 · 610 MW · 43 28 Aug 2024 · 169 MW · 43 29 Aug 2024 · 41 MW · 15 30 Aug 2024 · 9 MW · 4
21 Aug 23 Aug 25 Aug 27 Aug 29 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

37°high
56km/h · peak gust
20%lowest humidity

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

This area had burned before

89% of the perimeter overlaps earlier fires recorded since 2016: 1,210 ha in 2016, 2,613 ha in 2019, 4,292 ha in 2021. Part of it burned more than once, so the yearly figures add up to more than the 4,535 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 3.2% of the area of London (51 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. Oeiras 38,161 inhabitants where it started
    3,769 ha reached on 21 Aug
    1.4 %
  2. Cajazeiras do Piauí 3,108 inhabitants
    1,385 ha reached on 26 Aug
    2.7 %

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 area0.48 ha
Residents≈ 70

Inside the perimeter there were about 0.48 hectares of built-up land and about 70 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)
21 Aug 36.6 °C 25 % 41 km/h 0.0 mm Very high 49
22 Aug 35.7 °C 23 % 44 km/h 0.0 mm Extreme 50
23 Aug 34.6 °C 27 % 47 km/h 0.0 mm Extreme 52
24 Aug 34.8 °C 27 % 43 km/h 0.0 mm Very high 49
25 Aug 35.7 °C 26 % 42 km/h 0.0 mm Very high 50
26 Aug 37.2 °C 21 % 41 km/h 0.0 mm Very high 50
27 Aug 36.8 °C 21 % 46 km/h 0.0 mm Extreme 52
28 Aug 35.6 °C 21 % 50 km/h 0.0 mm Extreme 56
29 Aug 35.6 °C 20 % 51 km/h 0.0 mm Extreme 56
30 Aug 34.8 °C 20 % 56 km/h 0.0 mm Extreme 59
31 Aug after 35.5 °C 19 % 50 km/h 0.0 mm Extreme 55
1 Sept after 35.1 °C 14 % 53 km/h 0.0 mm Extreme 61
2 Sept after 35.6 °C 22 % 46 km/h 0.0 mm Extreme 57
3 Sept after 37.2 °C 20 % 42 km/h 0.0 mm Extreme 53
4 Sept after 37.0 °C 17 % 42 km/h 0.0 mm Extreme 54
5 Sept after 36.9 °C 19 % 42 km/h 0.0 mm Extreme 54
6 Sept after 37.1 °C 21 % 44 km/h 0.0 mm Extreme 56
7 Sept after 36.4 °C 24 % 48 km/h 0.0 mm Extreme 56
8 Sept after 36.9 °C 17 % 49 km/h 0.0 mm Extreme 59
9 Sept after 35.7 °C 23 % 51 km/h 0.0 mm Extreme 58

Before and after, from space

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

Before · 14 Aug 2024
After · 6 Sept 2024

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 25 August 2024 the air beside the fire reached 15 µg/m³ of PM2.5, but no daily average passed the WHO guideline (15).

PM2.5 peak15 µg/m³
Days over the guideline0 days
PM1023 µg/m³
Optical depth0.45
1920212223242526272829303112
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 · 188Every 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 Oeiras fire last?
GWIS (Copernicus) dates it between 21 August 2024 and 30 August 2024: 10 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 5,121 hectares (51.2 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 2 municipalities: Oeiras (3,769 ha, 1.4 %); Cajazeiras do Piauí (1,385 ha, 2.7 %).
What was the weather like?
During the fire the temperature reached 37.2 °C, humidity dropped to 20 % and gusts hit 56 km/h. The fire danger index (FWI) reached 59, 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 ›

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. 188 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.