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BR · Brazil · –

Antônio Almeida fire, August 2021 Uruçuí, Antônio Almeida

Out · last detection 9 Sept 2021, 15:48 UTC

The fire started on 27 August 2021 in Antônio Almeida, Brazil, and satellites saw it burning for 14 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 3,420 hectares from heat detections, spread across 2 municipalities.

It is the 537th largest in Piaui since 2016 (of 665 with a page). Number 681 in Brazil in 2021, of 814.

The power measured by the satellite is low (19.8 MW in the strongest hotspot), more typical of grass or stubble burning, or a slow surface fire, than of a large crown fire.

Burnt area
3,420ha
GWIS perimeter (Copernicus)
Duration
14days
27 Aug 2021 – 9 Sept 2021
Municipalities hit
2
municipalities
Started on
27 Aug
2021
Heat detections
100
in a single hotspot: 20 MW
Danger at start
47
Very high · FWI index
Average daily power
57MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 27 Aug9 Sept
9 Sept 2021

How it evolved, day by day

28 Aug 2021 · 113 MW · 15 29 Aug 2021 · 46 MW · 5 30 Aug 2021 · 99 MW · 19 1 Sept 2021 · 88 MW · 17 2 Sept 2021 · 80 MW · 21 3 Sept 2021 · 90 MW · 15 4 Sept 2021 · 7 MW · 1 5 Sept 2021 · 31 MW · 4 6 Sept 2021 · 15 MW · 2 9 Sept 2021 · 6 MW · 1
28 Aug 30 Aug 2 Sept 4 Sept 6 Sept

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

The weather it burned in

39°high
49km/h · peak gust
21%lowest humidity

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

This area had burned before

69% of the perimeter overlaps earlier fires recorded since 2016: 1,139 ha in 2017, 972 ha in 2018, 367 ha in 2019. Part of it burned more than once, so the yearly figures add up to more than the 2,356 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 2.2% of the area of London (34 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. Uruçuí 25,203 inhabitants
    1,837 ha reached on 29 Aug
    0.2 %
  2. Antônio Almeida 3,152 inhabitants where it started
    1,602 ha reached on 28 Aug
    2.5 %

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 2020
Built-up area0.48 ha
Residents< 20

Inside the perimeter there were about 0.48 hectares of built-up land and almost nobody lived there (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)

Started with 60 days without rain: 55 % of the area in Brazil

Day High Min. humidity Peak gust Rain Danger (FWI)
27 Aug 37.8 °C 26 % 40 km/h 0.0 mm Very high 47
28 Aug 37.7 °C 28 % 49 km/h 0.0 mm Extreme 52
29 Aug 37.9 °C 21 % 45 km/h 0.0 mm Extreme 51
30 Aug 37.2 °C 26 % 42 km/h 0.0 mm Very high 50
31 Aug 36.4 °C 31 % 43 km/h 0.0 mm Very high 44
1 Sept 35.5 °C 34 % 43 km/h 0.0 mm Very high 42
2 Sept 35.7 °C 29 % 39 km/h 0.0 mm Very high 42
3 Sept 37.5 °C 24 % 42 km/h 0.0 mm Very high 46
4 Sept 38.2 °C 28 % 42 km/h 0.0 mm Very high 46
5 Sept 38.3 °C 27 % 35 km/h 0.0 mm Very high 40
6 Sept 38.9 °C 25 % 28 km/h 0.0 mm Very high 40
7 Sept 38.3 °C 23 % 35 km/h 0.0 mm Very high 42
8 Sept 38.0 °C 23 % 41 km/h 0.0 mm Very high 48
9 Sept 38.0 °C 25 % 40 km/h 0.0 mm Very high 47
10 Sept after 38.2 °C 27 % 31 km/h 0.0 mm Very high 40
11 Sept after 39.0 °C 23 % 35 km/h 0.0 mm Very high 42
12 Sept after 37.9 °C 20 % 37 km/h 0.0 mm Very high 47
13 Sept after 38.6 °C 21 % 44 km/h 0.0 mm Extreme 51
14 Sept after 37.7 °C 25 % 39 km/h 0.0 mm Very high 49
15 Sept after 38.1 °C 27 % 39 km/h 0.0 mm Very high 49
16 Sept after 37.9 °C 22 % 39 km/h 0.0 mm Very high 49
17 Sept after 37.7 °C 21 % 48 km/h 0.0 mm Extreme 55
18 Sept after 37.2 °C 20 % 39 km/h 0.0 mm Extreme 51
19 Sept after 38.4 °C 23 % 38 km/h 0.0 mm Very high 49

Its twins: fires that started in the same weather

It started with an FWI of 46.6, a minimum humidity of 26% and more than two months without rain. Fires in the area that started in weather like this since 2016: 41.

FWI at the start 46.6
Minimum humidity 26 %
Days without rain 60+
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Porto Alegre do Piauí fire, October 2019
5,061 ha 6 days FWI 45.8 Min. humidity 26 % 44 km away, in 2019

First rain (1 mm or more) after it ended: 8.1 mm on 21 Oct.

What happened to them

11 days
median duration
4,287 ha
median area
10 %
went past 10,000 ha
1.8 mm
rain at the end (median; 14 of 41 had it)

It burned an area similar to its twins (3,420 ha against a median of 4,287 ha) and lasted 14 days, against 11 days.

In 27 of 41, not even 1 mm fell in the ten days after the end: they went out without rain. In the rest, the first rainy day brought a median of 1.8 mm.

This is a bank of analogues: it shows what usually happens, not what will happen. With fewer than 15 twins we give no figures. How we calculate it

How it ended

—first rain
—no rain in ten days
49km/h · max. gust

It was considered over on 9 Sept, and not even 1 mm fell in the following ten days: it went out without rain. Twins with rain when they ended: 14 of 41, with a median of 1.8 mm.

Weather on this page: Open-Meteo.com (CC BY 4.0) · Copernicus Climate Change Service (ERA5)

How a twin is chosen

  • Same area: fires that have already ended, less than 250 km from this one, since 2016.
  • Same start: we compare the FWI on the first day, the minimum humidity that day and the run of days without rain before it. The slider sets how much they may differ.
  • Only pages with final weather data (ERA5 reanalysis) calculated in the same way as this fire’s; agricultural and grass burns and pages with data under review are left out.
  • Fires burning at the same time as this one (a week before or after) are left out: they share the same spell of weather and do not count as a precedent.
  • They are sorted by similarity, and the outlines of the first five are drawn.

How we calculate it

Before and after, from space

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

Before · 20 Aug 2021
After · 16 Sept 2021

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 · 100Every 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 Antônio Almeida fire last?
According to the heat detections seen by satellite inside the perimeter, it burned from 27 August 2021 to 9 September 2021 (14 days). The perimeter dates it from 28 August 2021 to 4 September 2021.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 3,420 hectares (34.2 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 2 municipalities: Uruçuí (1,837 ha, 0.2 %); Antônio Almeida (1,602 ha, 2.5 %).
What was the weather like?
During the fire the temperature reached 38.9 °C, humidity dropped to 21 % and gusts hit 49 km/h. The fire danger index (FWI) reached 52, 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.
How did the fires that started in similar weather in this area end?
Fires less than 250 km away that started since 2016 with a similar FWI, humidity and dry spell: 41. Their median duration was 11 days and their median area 4,287 ha; 10 % went past 10,000 ha. In 27 of 41, not even 1 mm fell in the ten days after the end: they went out without rain. In the rest, the first rainy day brought a median of 1.8 mm.

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 · 2 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.
  1. Last day with fire: 4 September 2021 → 9 September 2021.
  2. Start date: 28 August 2021 → 27 August 2021.

RSS Changes to this page With cross-checks and a citable version

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 28 August 2021 to 4 September 2021. 100 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.

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.