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Loreto fire, 10 August 2023 Loreto

Out · last detection 19 Aug 2023, 15:55 UTC

The fire started on 10 August 2023 in Loreto, Brazil, and satellites saw it burning for 9 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 3,480 hectares from heat detections, spread across a single municipality.

It is the 456th largest in Maranhão since 2016 (of 607 with a page). Number 335 in Brazil in 2023, of 431.

Burnt area
3,480ha
GWIS perimeter (Copernicus)
Duration
9days
10 Aug 2023 – 18 Aug 2023
Municipalities hit
1
municipalities
Started on
10 Aug
2023
Heat detections
105
in a single hotspot: 43 MW
Danger at start
50
Very high · FWI index
Energy released
801MW
sum of detected power

Where it burned

19 Aug 2023
HOTSPOTS BY DAY 10 Aug18 Aug

How it evolved, day by day

101112131415161719

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
47km/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

58% of the perimeter overlaps earlier fires recorded since 2016: 545 ha in 2016, 49 ha in 2019, 87 ha in 2020, 913 ha in 2021, 681 ha in 2022. Part of it burned more than once, so the yearly figures add up to more than the 2,033 ha that had burned before.

What happened to each town

  1. Loreto 11,597 inhabitants where it started
    3,504 ha reached on 10 Aug
    1.0 %

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)
10 Aug 36.2 °C 20 % 40 km/h 0.0 mm Very high 50
11 Aug 36.3 °C 20 % 40 km/h 0.0 mm Extreme 50
12 Aug 36.7 °C 18 % 36 km/h 0.0 mm Very high 48
13 Aug 36.0 °C 18 % 37 km/h 0.0 mm Very high 48
14 Aug 35.8 °C 19 % 40 km/h 0.0 mm Extreme 51
15 Aug 35.5 °C 21 % 44 km/h 0.0 mm Extreme 52
16 Aug 35.8 °C 24 % 45 km/h 0.0 mm Extreme 54
17 Aug 35.9 °C 20 % 45 km/h 0.0 mm Extreme 54
18 Aug 36.8 °C 21 % 40 km/h 0.0 mm Extreme 50
19 Aug after 37.0 °C 23 % 44 km/h 0.0 mm Extreme 52
20 Aug after 36.7 °C 26 % 47 km/h 0.0 mm Extreme 54
21 Aug after 38.9 °C 22 % 44 km/h 0.0 mm Extreme 51
22 Aug after 37.3 °C 27 % 31 km/h 0.2 mm Very high 43
23 Aug after 36.3 °C 28 % 42 km/h 0.0 mm Very high 48
24 Aug after 37.9 °C 23 % 28 km/h 0.0 mm Very high 39
25 Aug after 36.9 °C 31 % 22 km/h 0.0 mm Very high 38
26 Aug after 36.0 °C 36 % 26 km/h 0.0 mm High 36
27 Aug after 36.3 °C 36 % 20 km/h 0.1 mm High 33
28 Aug after 34.9 °C 42 % 25 km/h 0.3 mm High 31
29 Aug after 34.9 °C 42 % 30 km/h 0.5 mm High 30
30 Aug after 36.8 °C 29 % 34 km/h 0.0 mm High 36
31 Aug after 35.6 °C 40 % 19 km/h 0.5 mm High 32
1 Sept after 34.5 °C 38 % 31 km/h 0.3 mm High 32
2 Sept after 36.2 °C 24 % 42 km/h 0.0 mm Very high 46
3 Sept after 37.0 °C 21 % 42 km/h 0.0 mm Very high 48

Before and after, from space

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

Before · 3 Aug 2023
After · 25 Aug 2023

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 20 August 2023 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
PM1031 µg/m³
Optical depth0.40
89101112131415161718192021
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 · 105Every 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 Loreto fire last?
GWIS (Copernicus) dates it between 10 August 2023 and 18 August 2023: 9 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 3,480 hectares (34.8 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire only entered Loreto (3,504 ha, 1.0 %).
What was the weather like?
During the fire the temperature reached 38.9 °C, humidity dropped to 18 % and gusts hit 47 km/h. The fire danger index (FWI) reached 54, 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

Satellite cross-check

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.

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.