How long did the Loreto fire last?

GWIS (Copernicus) dates it between 15 August 2025 and 22 August 2025: 8 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 3,026 hectares (30.3 km²). It is an estimate: official national figures may differ.

Which municipalities burned?

The fire only entered Loreto (3,048 ha, 0.8 %).

What was the weather like?

During the fire the temperature reached 36.4 °C, humidity dropped to 18 % and gusts hit 44 km/h. The fire danger index (FWI) reached 51, 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 · 2025-08-15 → 2025-08-22

Loreto fire, August 2025 Loreto

Out · last detection 22 Aug 2025, 16:33 UTC

The fire started on 15 August 2025 in Loreto, Brazil, and satellites saw it burning for 8 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 3,026 hectares from heat detections, spread across a single municipality.

It is the 596th largest in Maranhão since 2016 (of 607 with a page). Number 704 in Brazil in 2025, of 714.

Burnt area: 3,026ha; GWIS perimeter (Copernicus)
Duration: 8days; 15 Aug 2025 – 22 Aug 2025
Municipalities hit: 1; municipalities
Started on: 15 Aug; 2025
Heat detections: 72; in a single hotspot: 87 MW
Danger at start: 42; Very high · FWI index
Energy released: 580MW; sum of detected power

Play back 22 Aug 2025

HOTSPOTS BY DAY 15 Aug22 Aug

How it evolved, day by day

1516171819202122

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

44km/h · peak gust

18%lowest humidity

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

This area had burned before

80% of the perimeter overlaps earlier fires recorded since 2016: 967 ha in 2017, 102 ha in 2019, 1,285 ha in 2021, 67 ha in 2022, 2,047 ha in 2023, 4 ha in 2024. Part of it burned more than once, so the yearly figures add up to more than the 2,407 ha that had burned before.

What happened to each town

Loreto 11,597 inhabitants where it started

3,048 ha reached on 15 Aug

0.8 %

Burnt area inside each municipality, from crossing the GWIS perimeter with administrative boundaries. The distance is from the town centre to the nearest fire: staying a kilometre away does not mean it reached the houses.

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)
9 Aug	35.3 °C	22 %	32 km/h	0.0 mm	Very high 42
10 Aug	34.1 °C	34 %	24 km/h	0.0 mm	High 34
11 Aug	34.8 °C	37 %	29 km/h	0.3 mm	High 34
12 Aug	32.8 °C	40 %	26 km/h	0.7 mm	High 25
13 Aug	32.0 °C	44 %	34 km/h	0.1 mm	High 26
14 Aug	35.8 °C	24 %	36 km/h	0.0 mm	Very high 41
15 Aug	36.4 °C	20 %	36 km/h	0.0 mm	Very high 45
16 Aug	35.0 °C	22 %	38 km/h	0.0 mm	Very high 49
17 Aug	34.7 °C	22 %	38 km/h	0.0 mm	Very high 47
18 Aug	35.4 °C	22 %	33 km/h	0.0 mm	Very high 45
19 Aug	34.9 °C	22 %	41 km/h	0.0 mm	Very high 50
20 Aug	34.3 °C	18 %	44 km/h	0.0 mm	Extreme 51
21 Aug	34.8 °C	22 %	40 km/h	0.0 mm	Very high 49
22 Aug	35.6 °C	22 %	43 km/h	0.0 mm	Extreme 51
23 Aug after	36.1 °C	20 %	40 km/h	0.0 mm	Extreme 50
24 Aug after	35.9 °C	19 %	38 km/h	0.0 mm	Very high 49
25 Aug after	36.9 °C	18 %	38 km/h	0.0 mm	Very high 49
26 Aug after	35.8 °C	22 %	34 km/h	0.0 mm	Very high 48
27 Aug after	36.6 °C	17 %	31 km/h	0.0 mm	Very high 44
28 Aug after	36.8 °C	19 %	32 km/h	0.0 mm	Very high 47
29 Aug after	36.7 °C	20 %	38 km/h	0.0 mm	Extreme 52
30 Aug after	36.4 °C	19 %	38 km/h	0.0 mm	Extreme 51
31 Aug after	36.6 °C	17 %	38 km/h	0.0 mm	Extreme 51
1 Sept after	36.7 °C	17 %	44 km/h	0.0 mm	Extreme 55

Before and after, from space

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

↔

Before · 8 Aug 2025

After · 29 Aug 2025

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 25 August 2025 the air beside the fire reached 22 µg/m³ of PM2.5, but no daily average passed the WHO guideline (15).

PM2.5 peak22 µg/m³

Days over the guideline0 days

PM1022 µg/m³

Optical depth0.41

WHO 15

13141516171819202122232425

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 · 72Every 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 Loreto fire last?: GWIS (Copernicus) dates it between 15 August 2025 and 22 August 2025: 8 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 3,026 hectares (30.3 km²). It is an estimate: official national figures may differ.
Which municipalities burned?: The fire only entered Loreto (3,048 ha, 0.8 %).
What was the weather like?: During the fire the temperature reached 36.4 °C, humidity dropped to 18 % and gusts hit 44 km/h. The fire danger index (FWI) reached 51, 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

INPE · Programa Queimadas ↗
IBAMA · Prevfogo ↗

Satellite cross-check

NASA FIRMS ↗
GWIS · Copernicus ↗

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 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.

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