Brejo do Piauí fire, 12 August 2021 Brejo do Piauí
The fire started on 12 August 2021 in Brejo do Piauí, Brazil, and satellites saw it burning for 13 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 4,390 hectares from heat detections, spread across a single municipality.
It is the 444th largest in Piaui since 2016 (of 805 with a page). Number 480 in Brazil in 2021, of 814.
Compare with…
- Burnt area
- 4,390ha
- GWIS perimeter (Copernicus)
- Duration
- 13days
- 12 Aug 2021 – 24 Aug 2021
- Municipalities hit
- 1
- municipalities
- Started on
- 12 Aug
- 2021
- Heat detections
- 239
- in a single hotspot: 101 MW
- Danger at start
- 50
- Very high · FWI index
- Average daily power
- 226MW
- detected power per day, on average
Where it burned
How it evolved, day by day
Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.
The weather it burned in
It had gone more than two months 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?
London boundary: geoBoundaries · Office for National Statistics (Open Government Licence v3.0).
Paris boundary: geoBoundaries · Institut national de l'information géographique et forestière (IGN-F) (Etalab Open License 2.0).
Madrid boundary: geoBoundaries · Open Data ESRI, IGN Central Registry of Cartography Area (CC BY 4.0).
Berlin boundary: geoBoundaries · Federal Agency for Cartography and Geodesy (dl-de/by-2-0).
This compares size, not location: both shapes are at the same scale, north up, centred on each other.
What happened to each town
-
4,416 ha reached on 12 Aug1.9 %
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 2020Inside the perimeter there were about 0.47 hectares of built-up land and about 30 residents (GHSL 2020, 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) |
|---|---|---|---|---|---|
| 12 Aug | 36.9 °C | 23 % | 43 km/h | 0.0 mm | Very high 50 |
| 13 Aug | 35.7 °C | 26 % | 46 km/h | 0.0 mm | Extreme 53 |
| 14 Aug | 35.5 °C | 23 % | 43 km/h | 0.0 mm | Extreme 50 |
| 15 Aug | 34.8 °C | 25 % | 40 km/h | 0.0 mm | Very high 48 |
| 16 Aug | 35.6 °C | 18 % | 39 km/h | 0.0 mm | Very high 50 |
| 17 Aug | 35.6 °C | 16 % | 44 km/h | 0.0 mm | Extreme 52 |
| 18 Aug | 34.2 °C | 22 % | 50 km/h | 0.0 mm | Extreme 56 |
| 19 Aug | 34.1 °C | 25 % | 51 km/h | 0.0 mm | Extreme 55 |
| 20 Aug | 34.3 °C | 27 % | 45 km/h | 0.0 mm | Very high 50 |
| 21 Aug | 35.1 °C | 22 % | 45 km/h | 0.0 mm | Extreme 50 |
| 22 Aug | 35.8 °C | 21 % | 48 km/h | 0.0 mm | Extreme 53 |
| 23 Aug | 35.9 °C | 25 % | 43 km/h | 0.0 mm | Very high 49 |
| 24 Aug | 36.1 °C | 26 % | 41 km/h | 0.0 mm | Extreme 51 |
| 25 Aug after | 36.1 °C | 25 % | 42 km/h | 0.0 mm | Very high 49 |
| 26 Aug after | 37.2 °C | 22 % | 43 km/h | 0.0 mm | Extreme 50 |
| 27 Aug after | 37.1 °C | 23 % | 43 km/h | 0.0 mm | Extreme 50 |
| 28 Aug after | 36.2 °C | 27 % | 48 km/h | 0.0 mm | Extreme 53 |
| 29 Aug after | 36.4 °C | 21 % | 45 km/h | 0.0 mm | Extreme 52 |
| 30 Aug after | 36.8 °C | 24 % | 42 km/h | 0.0 mm | Extreme 50 |
| 31 Aug after | 35.4 °C | 27 % | 41 km/h | 0.0 mm | Very high 49 |
| 1 Sept after | 36.2 °C | 26 % | 41 km/h | 0.0 mm | Extreme 51 |
| 2 Sept after | 34.4 °C | 26 % | 41 km/h | 0.0 mm | Extreme 50 |
| 3 Sept after | 36.9 °C | 21 % | 40 km/h | 0.0 mm | Very high 50 |
Before and after, from space
Drag the line to compare the same ground before the fire and after it.
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 · 239Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
- 9,238 haRibeira do Piauí4 September 2020 · 18 days · 8 km away
- 15,730 haRibeira do Piauí27 September 2020 · 14 days · 18 km away
- 30,487 haBrejo do PiauíAugust 2020 · 55 days · 33 km away
- 10,166 haPedro LaurentinoSeptember 2024 · 11 days · 33 km away
- 18,374 haTamboril do PiauíSeptember 2021 · 29 days · 36 km away
- 16,639 haJoão CostaAugust 2020 · 26 days · 37 km away
Frequently asked questions
- How long did the Brejo do Piauí fire last?
- GWIS (Copernicus) dates it between 12 August 2021 and 24 August 2021: 13 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 4,390 hectares (43.9 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire only entered Brejo do Piauí (4,416 ha, 1.9 %).
- What was the weather like?
- During the fire the temperature reached 36.9 °C, humidity dropped to 16 % and gusts hit 51 km/h. The fire danger index (FWI) reached 56, 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.
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
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. 239 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 2020, 100 m cells), summed inside the perimeter: an estimate of what was there, not a damage count.
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.