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.
This is an index computed from weather model data, not a measurement of the fire nor an official warning. Danger warnings are issued by each country’s authority. Emergency number and official warnings ›
Weather during the fire
model
25.4°C · 27% RH
High of 25.4 °C and minimum humidity of 27% on 24 September 2025; gusts of 63 km/h on 21 September 2025.
These are model values for a cell of about 25 km, not from a weather station: they may differ from what was measured on the ground.
ⓘThis page’s change log has been kept since 24 October 2026: every night what it publishes is compared and the difference is logged. Anything earlier is reconstructed from each source’s date and marked as reconstructed.
Show
· reconstructedofficial
Matched with the official ICNF record
Matches: 2,100 ha in the official record (records: 1).
A version keeps the area, dates, name and official record; the area as it was logged (changes under 2% are not logged). The map, hotspots and weather always show today’s data.
Citation
A lede of about 60 words figures only, no adjectives
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.
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)
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 start53.3
Minimum humidity41 %
Days without rain60+
this firechosen twinsrest of the area
Almost identicalSimilar
Outlines of the closest twins
This fire · Aljezur fire, September 2025
2,332 ha4 daysFWI 53.3Min. humidity 41 %
Silves fire, September 2016
176 ha2 daysFWI 52.9Min. humidity 37 %30 km away, in 2016
First rain (1 mm or more) after it ended: 4.1 mm on 13 Sept.
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.
Drag the line to compare the same ground before the fire and after it.
↔
Before · 14 Sept 2025
After · 1 Oct 2025
Sentinel-2 did not pass over on that day. Try another date, or use false colour, which is daily.
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 peak57µg/m³
Days over the guideline1day
PM1075µg/m³
Optical depth0.50
WHO 15
19 Sept21 Sept23 Sept25 Sept27 Sept
GoodFairModeratePoorVery poorExtremely 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 CSVTimes in UTC. Each detection is a 375 m pixel: a large fire yields hundreds per pass.
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.
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 errorHow 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.
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.