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Teresina fire, September 2025 Teresina, Nazária, Demerval Lobão

Out · last detection 5 Oct 2025, 16:10 UTC

The fire started on 17 September 2025 in Teresina, Brazil, and satellites saw it burning for 19 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 3,532 hectares from heat detections, spread across 3 municipalities.

It is the 617th largest in Piaui since 2016 (of 805 with a page). Number 558 in Brazil in 2025, of 714.

Compare with…

Suggestions: Nazária · 2025Curralinhos · 2025Curralinhos · 2016

Burnt area
3,532ha
GWIS perimeter (Copernicus)
Duration
19days
17 Sept 2025 – 5 Oct 2025
Municipalities hit
3
municipalities
Started on
17 Sept
2025
Heat detections
89
in a single hotspot: 31 MW
Danger at start
46
Very high · FWI index
Average daily power
47MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 17 Sept5 Oct
5 Oct 2025

How it evolved, day by day

17 Sept 2025 · 116 MW · 6 18 Sept 2025 · 51 MW · 4 19 Sept 2025 · 8 MW · 2 23 Sept 2025 · 48 MW · 6 24 Sept 2025 · 14 MW · 3 25 Sept 2025 · 25 MW · 4 26 Sept 2025 · 47 MW · 6 27 Sept 2025 · 10 MW · 6 28 Sept 2025 · 62 MW · 14 29 Sept 2025 · 7 MW · 2 30 Sept 2025 · 97 MW · 5 1 Oct 2025 · 121 MW · 17 2 Oct 2025 · 69 MW · 9 3 Oct 2025 · 25 MW · 2 5 Oct 2025 · 9 MW · 3
17 Sept 23 Sept 26 Sept 29 Sept 1 Oct 2 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

39°high
45km/h · peak gust
19%lowest humidity

It had gone 34 days without rain (1 mm or more) when it started.

This area had burned before

61% of the perimeter overlaps earlier fires recorded since 2016: 1,182 ha in 2016, 1,255 ha in 2017. Part of it burned more than once, so the yearly figures add up to more than the 2,152 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 2.2% of the area of London (35 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. Teresina 866,300 inhabitants where it started
    3,442 ha reached on 17 Sept
    2.5 %
  2. Nazária 10,262 inhabitants
    60 ha reached on 1 Oct
    0.2 %
  3. Demerval Lobão 16,352 inhabitants
    54 ha
    0.2 %

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 area1.6 ha
Residents≈ 50

Inside the perimeter there were about 1.6 hectares of built-up land and about 50 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)
17 Sept 37.6 °C 24 % 40 km/h 0.0 mm Very high 46
18 Sept 38.5 °C 22 % 39 km/h 0.0 mm Very high 45
19 Sept 38.1 °C 24 % 34 km/h 0.0 mm Very high 43
20 Sept 37.4 °C 23 % 31 km/h 0.0 mm Very high 41
21 Sept 37.4 °C 26 % 38 km/h 0.0 mm Very high 46
22 Sept 36.7 °C 30 % 40 km/h 0.0 mm Very high 44
23 Sept 38.6 °C 24 % 39 km/h 0.0 mm Very high 43
24 Sept 38.7 °C 19 % 41 km/h 0.0 mm Very high 48
25 Sept 37.6 °C 23 % 45 km/h 0.0 mm Extreme 51
26 Sept 37.7 °C 25 % 40 km/h 0.0 mm Very high 48
27 Sept 37.0 °C 24 % 40 km/h 0.0 mm Very high 48
28 Sept 37.0 °C 24 % 41 km/h 0.0 mm Extreme 52
29 Sept 37.0 °C 28 % 43 km/h 0.0 mm Very high 49
30 Sept 38.5 °C 23 % 42 km/h 0.0 mm Very high 48
1 Oct 37.6 °C 25 % 42 km/h 0.0 mm Very high 47
2 Oct 37.7 °C 27 % 41 km/h 0.0 mm Very high 48
3 Oct 37.1 °C 24 % 41 km/h 0.0 mm Very high 48
4 Oct 37.8 °C 19 % 42 km/h 0.0 mm Very high 49
5 Oct 38.1 °C 22 % 40 km/h 0.0 mm Very high 48
6 Oct after 38.2 °C 25 % 36 km/h 0.0 mm Very high 46
7 Oct after 38.5 °C 25 % 38 km/h 0.0 mm Very high 48
8 Oct after 38.3 °C 26 % 41 km/h 0.0 mm Very high 49
9 Oct after 37.5 °C 28 % 39 km/h 0.0 mm Very high 47
10 Oct after 39.2 °C 23 % 37 km/h 0.0 mm Very high 46
11 Oct after 38.7 °C 22 % 33 km/h 0.0 mm Very high 42
12 Oct after 38.9 °C 20 % 36 km/h 0.0 mm Very high 45
13 Oct after 38.2 °C 24 % 40 km/h 0.0 mm Very high 45
14 Oct after 39.5 °C 17 % 36 km/h 0.0 mm Very high 49
15 Oct after 39.2 °C 17 % 38 km/h 0.0 mm Extreme 50

Before and after, from space

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

Before · 10 Sept 2025
After · 12 Oct 2025

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 6 October 2025 the air beside the fire reached 57 µg/m³ of PM2.5. That day averaged 30: 2.0 times the WHO daily guideline (15).

PM2.5 peak57 µg/m³
Days over the guideline5 days
PM1058 µg/m³
Optical depth0.47
202122232425262728293012345678
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 · 89Every 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 Teresina fire last?
According to the heat detections seen by satellite inside the perimeter, it burned from 17 September 2025 to 5 October 2025 (19 days). The perimeter dates it from 22 September 2025 to 5 October 2025.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 3,532 hectares (35.3 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 3 municipalities: Teresina (3,442 ha, 2.5 %); Nazária (60 ha, 0.2 %); Demerval Lobão (54 ha, 0.2 %).
What was the weather like?
During the fire the temperature reached 38.7 °C, humidity dropped to 19 % and gusts hit 45 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.

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: 22 September 2025 → 17 September 2025.

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 22 September 2025 to 5 October 2025. 89 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.