How long did the Assunção do Piauí fire last?

According to the heat detections seen by satellite inside the perimeter, it burned from 1 October 2026 to 21 October 2026 (21 days). The perimeter dates it from 2 October 2026 to 14 October 2026.

How much area did it burn?

The perimeter GWIS (Copernicus) rebuilt from heat detections is 5,141 hectares (51.4 km²). It is an estimate: official national figures may differ.

Which municipalities burned?

The fire only entered Assunção do Piauí (5,176 ha, 3.0 %).

Is the Assunção do Piauí fire still active?

No fire detections since 21 Oct 2026, 16:37 UTC. A lack of detections is not an official extinction.

What was the weather like?

During the fire the temperature reached 35.7 °C, humidity dropped to 18 % and gusts hit 63 km/h. The fire danger index (FWI) reached 68, 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.

BR · Brazil · 2026-10-01 → 2026-10-21

Assunção do Piauí fire, October 2026 Assunção do Piauí

Out · last detection 21 Oct 2026, 16:37 UTC

The fire started on 1 October 2026 in Assunção do Piauí, Brazil, and satellites saw it burning for 21 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 5,141 hectares from heat detections, spread across a single municipality.

It is the 326th largest in Piaui since 2016 (of 805 with a page). Number 338 in Brazil in 2026, of 769.

Compare with…

Suggestions: Quiterianópolis · 2025 Pimenteiras · 2025 Pimenteiras · 2020 Pimenteiras · 2019

Burnt area: 5,141ha; GWIS perimeter (Copernicus)
Duration: 21days; 1 Oct 2026 – 21 Oct 2026
Municipalities hit: 1; municipalities
Started on: 1 Oct; 2026
Heat detections: 270; in a single hotspot: 313 MW
Danger at start: 50; Very high · FWI index
Average daily power: 502MW; detected power per day, on average

HOTSPOTS BY DAY 1 Oct21 Oct

Play back 21 Oct 2026

How it evolved, day by day

1 Oct 5 Oct 8 Oct 9 Oct 11 Oct 14 Oct 17 Oct

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

63km/h · peak gust

18%lowest humidity

It had gone 5 days without rain (1 mm or more) when it started. Rain came after the fire: 1.0 mm on 28 Oct.

This area had burned before

22% of the perimeter overlaps earlier fires recorded since 2016: 1,097 ha in 2019, 123 ha in 2020. Part of it burned more than once, so the yearly figures add up to more than the 1,128 ha that had burned before.

How big is it?

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

Assunção do Piauí 7,452 inhabitants where it started

5,176 ha reached on 1 Oct

3.0 %

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 area0.53 ha

Residents< 20

Inside the perimeter there were about 0.53 hectares of 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) · forecast models, provisional until the ERA5 reanalysis arrives

Day	High	Min. humidity	Peak gust	Rain	Danger (FWI)
1 Oct	33.7 °C	33 %	56 km/h	0.1 mm	Very high 50
2 Oct	32.4 °C	36 %	53 km/h	0.3 mm	Very high 49
3 Oct	32.1 °C	34 %	53 km/h	0.0 mm	Extreme 50
4 Oct	34.2 °C	24 %	53 km/h	0.0 mm	Extreme 52
5 Oct	33.8 °C	18 %	54 km/h	0.0 mm	Extreme 59
6 Oct	34.0 °C	20 %	48 km/h	0.2 mm	Extreme 54
7 Oct	34.5 °C	20 %	55 km/h	0.0 mm	Extreme 60
8 Oct	34.9 °C	22 %	56 km/h	0.0 mm	Extreme 62
9 Oct	34.6 °C	25 %	62 km/h	0.0 mm	Extreme 68
10 Oct	34.6 °C	29 %	47 km/h	0.0 mm	Extreme 53
11 Oct	34.2 °C	26 %	53 km/h	0.1 mm	Extreme 56
12 Oct	34.8 °C	21 %	57 km/h	0.0 mm	Extreme 62
13 Oct	34.2 °C	24 %	63 km/h	0.0 mm	Extreme 66
14 Oct	35.2 °C	19 %	57 km/h	0.0 mm	Extreme 65
15 Oct	35.7 °C	23 %	56 km/h	0.0 mm	Extreme 64
16 Oct	35.5 °C	27 %	42 km/h	0.0 mm	Extreme 50
17 Oct	34.4 °C	31 %	60 km/h	0.7 mm	Extreme 54
18 Oct	33.7 °C	34 %	44 km/h	0.0 mm	Very high 44
19 Oct	34.0 °C	29 %	37 km/h	0.0 mm	Very high 38
20 Oct	34.3 °C	27 %	58 km/h	0.1 mm	Extreme 54
21 Oct	35.1 °C	21 %	57 km/h	0.0 mm	Extreme 60
22 Oct after	34.2 °C	24 %	53 km/h	0.5 mm	Extreme 59
23 Oct after	34.1 °C	29 %	56 km/h	0.2 mm	Extreme 58
24 Oct after	36.0 °C	22 %	57 km/h	0.0 mm	Extreme 61
25 Oct after	35.1 °C	29 %	53 km/h	0.1 mm	Extreme 56
26 Oct after	35.2 °C	29 %	44 km/h	0.0 mm	Extreme 54
27 Oct after	34.8 °C	29 %	35 km/h	0.7 mm	Very high 40
28 Oct after	33.8 °C	35 %	46 km/h	1.0 mm	High 37

Before and after, from space

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

↔

Before · 24 Sept 2026

After · 28 Oct 2026

Before After

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 4 October 2026 the air beside the fire reached 12 µg/m³ of PM2.5, but no daily average passed the WHO guideline (15).

PM2.5 peak12 µg/m³

Days over the guideline0 days

PM1016 µg/m³

Optical depth0.31

293012345678

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 · 270Every 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 time	Satellite	FRP (MW)	Lat	Lon

Other fires nearby

All fires in Brazil ›

Frequently asked questions

How long did the Assunção do Piauí fire last?: According to the heat detections seen by satellite inside the perimeter, it burned from 1 October 2026 to 21 October 2026 (21 days). The perimeter dates it from 2 October 2026 to 14 October 2026.
How much area did it burn?: The perimeter GWIS (Copernicus) rebuilt from heat detections is 5,141 hectares (51.4 km²). It is an estimate: official national figures may differ.
Which municipalities burned?: The fire only entered Assunção do Piauí (5,176 ha, 3.0 %).
Is the Assunção do Piauí fire still active?: No fire detections since 21 Oct 2026, 16:37 UTC. A lack of detections is not an official extinction.
What was the weather like?: During the fire the temperature reached 35.7 °C, humidity dropped to 18 % and gusts hit 63 km/h. The fire danger index (FWI) reached 68, 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 ›

INPE · Programa Queimadas ↗
IBAMA · Prevfogo ↗

Satellite cross-check

NASA FIRMS ↗
GWIS · Copernicus ↗

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.

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What do you think is wrong?

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What really happened?

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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 2 October 2026 to 14 October 2026. 270 Suomi-NPP VIIRS detections on those dates.
We have not matched this page with any official record.
Weather: ECMWF IFS model, provisional until the ERA5 reanalysis arrives.
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.

Where it burned