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PT · Portugal · –

Aljezur fire, September 2025 União das Freguesias de Bensafrim e Barão de São João, Bordeira, Barão de São Miguel

Out · last detection 24 Sept 2025, 03:25 UTC

The fire started on 21 September 2025 in União das Freguesias de Bensafrim e Barão de São João, Portugal, and satellites saw it burning for 4 days. Copernicus mapped a burnt perimeter of 2,332 hectares from satellite imagery, spread across 4 freguesias. According to ICNF, it was detected on 21 September 2025 at 12:21 and declared extinguished on 26 September 2025.

Number 16 in Portugal in 2025, of 85.

Burnt area
2,332ha
Copernicus perimeter
Duration
4days
21 Sept 2025 – 24 Sept 2025
Freguesias hit
4
freguesias
Started on
21 Sept
2025
Heat detections
143
in a single hotspot: 227 MW
Danger at start
53
Extreme · FWI index
Average daily power
544MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 21 Sept24 Sept
24 Sept 2025

How it evolved, day by day

21 Sept 2025 · 1,205 MW · 17 22 Sept 2025 · 843 MW · 89 23 Sept 2025 · 70 MW · 29 24 Sept 2025 · 59 MW · 8
21 Sept 22 Sept 23 Sept 24 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

25°high
63km/h · peak gust
24%lowest humidity

It had gone more than two months without rain (1 mm or more) when it started. Rain came after the fire: 3.2 mm on 28 Sept.

This area had burned before

No earlier perimeters overlap this fire since 2016, when the satellite record begins.

How big is it?

10 km
It burned the equivalent of 1.5% of the area of London (23 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 freguesia

  1. União das Freguesias de Bensafrim e Barão de São João 1,530 inhabitants · 3.7 km from the centre where it started
    1,563 ha reached on 22 Sept
    12 %
  2. Bordeira 370 inhabitants
    773 ha reached on 21 Sept
    9.7 %
  3. Barão de São Miguel 586 inhabitants · 2.1 km from the centre
    0 ha
    0.0 %
  4. Aljezur 3,455 inhabitants · 8.3 km from the centre
    0 ha
    0.0 %

Burnt area inside each freguesia, from crossing the official 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.

What burned

  • Scrub and transitional woodland47 %
  • Broadleaved forest34 %
  • Coniferous forest10 %
  • Sclerophyllous scrub5.7 %
  • Agricultural areas3.3 %

Natura 2000 protected area affected: 59 %

Natura 2000 sites (European Environment Agency, 2024 release) crossed by the perimeter.

Land cover inside the perimeter according to Corine Land Cover, as reported by Copernicus.

Official record

According to ICNF, this fire started on 21 September 2025 and burned 2,100 ha (the satellite measured 2,332 ha).

ICNF (Instituto da Conservação da Natureza e das Florestas). This is the agency’s operational record: its figures may be revised when the year’s statistics are closed.

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 Extreme FWI: 24 % of the area in Portugal Strong wind: 11 % of the area in Portugal 60 days without rain: 1.1 % of the area in Portugal

Day High Min. humidity Peak gust Rain Danger (FWI)
21 Sept 22.2 °C 41 % 63 km/h 0.0 mm Extreme 53
22 Sept 22.3 °C 29 % 49 km/h 0.0 mm Very high 47
23 Sept 24.5 °C 24 % 29 km/h 0.0 mm Very high 43
24 Sept 25.4 °C 27 % 26 km/h 0.0 mm High 32
25 Sept after 24.6 °C 30 % 25 km/h 0.0 mm High 35
26 Sept after 25.3 °C 30 % 31 km/h 0.0 mm High 31
27 Sept after 21.7 °C 50 % 38 km/h 0.0 mm High 33
28 Sept after 20.0 °C 75 % 66 km/h 3.2 mm High 24

Its twins: fires that started in the same weather

It started with an FWI of 53.3, a minimum humidity of 41% and more than two months without rain. Fires in the area that started in weather like this since 2016: 6.

FWI at the start 53.3
Minimum humidity 41 %
Days without rain 60+
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Silves fire, September 2016
176 ha 2 days FWI 52.9 Min. humidity 37 % 30 km away, in 2016

First rain (1 mm or more) after it ended: 4.1 mm on 13 Sept.

What happened to them

Fires in the area that started in similar weather: 6. With fewer than 15 we give no figures: they would be more noise than signal.

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

3.2 mmfirst rain
28 Sept4 days after it ended
63km/h · max. gust

It was considered over on 24 Sept, and on 28 Sept 3.2 mm fell. We do not know whether the rain or the firefighters put it out.

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 · 14 Sept 2025
After · 1 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 24 September 2025 the air beside the fire reached 57 µg/m³ of PM2.5. That day averaged 17: 1.1 times the WHO daily guideline (15).

PM2.5 peak57 µg/m³
Days over the guideline1 day
PM1075 µg/m³
Optical depth0.50
19 Sept21 Sept23 Sept25 Sept27 Sept
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 · 143Every 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 Portugal

Frequently asked questions

How long did the Aljezur fire last?
Copernicus dates it between 21 September 2025 and 24 September 2025: 4 days between the first and last image with fire. According to ICNF, it was detected on 21 September 2025 at 12:21 and declared extinguished on 26 September 2025.
How much area did it burn?
The perimeter Copernicus measured from satellite imagery is 2,332 hectares (23.3 km²). Official national figures may differ.
Which freguesias burned?
The fire entered 4 freguesias: União das Freguesias de Bensafrim e Barão de São João (1,563 ha, 12 %); Bordeira (773 ha, 9.7 %); Barão de São Miguel (0 ha, 0.0 %); Aljezur (0 ha, 0.0 %).
Did the fire reach a town?
The fire came within 2.1 km of the centre of Barão de São Miguel, the closest of the areas it touched. That is the distance from the perimeter, or the nearest hotspot, to the point marking the centre; it does not mean it entered the houses.
What was the weather like?
During the fire the temperature reached 25.4 °C, humidity dropped to 24 % and gusts hit 63 km/h. The fire danger index (FWI) reached 53, class Extreme.
Where does this data come from?
From the EFFIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Portugal (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: 112 · Emergency number and official warnings

Satellite cross-check

History of this page Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.

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 112.

How we know this
  • Perimeter: EFFIS (Copernicus), mapped on satellite imagery.
  • Dates from the perimeter: the VIIRS detections inside it did not change them. 143 Suomi-NPP VIIRS detections on those dates.
  • Compared with ICNF: 2,100 official ha against 2,332 ha of perimeter; they agree within 25%.
  • Weather: Copernicus ERA5 reanalysis at the fire location, in cells of about 25 km.

How we build fire pages: methodology

Where this data comes from

The perimeter and land cover come from the Copernicus European Forest Fire Information System (EFFIS), measured on MODIS and Sentinel-2 imagery and published under CC BY 4.0. Heat detections come from the VIIRS sensors aboard Suomi-NPP and NOAA-20, distributed by NASA FIRMS at 375 m resolution. Freguesia boundaries come from geoBoundaries ADM3 (CC0 1.0 Universal (CC0 1.0) Public Domain Dedication). The area per freguesia is computed by WorldFires by crossing the perimeter with those boundaries, so it may differ slightly from each country’s official figure.