The fire started on 25 August 2025 in Vale, Portugal, and satellites saw it burning for 3 days. Copernicus mapped a burnt perimeter of 218 hectares from satellite imagery, spread across 4 freguesias. According to ICNF, the largest of the 2 recorded fires was detected on 26 August 2025 at 15:32 and declared extinguished on 27 August 2025.
It is the 13th largest in Arcos de Valdevez since 2016 (of 29 with a page). Number 58 in Portugal in 2025, of 85.
The power measured by the satellite is low (3.6 MW in the strongest hotspot), more typical of grass or stubble burning, or a slow surface fire, than of a large crown fire.
Perimeter published by EFFIS (Copernicus).
ICNF: 221 ha (matched records: 2). Difference between the page and the official record: −1.3%. Matched on 8 November 2026.
25 Aug 2025 to 27 Aug 2025: first and last day with fire on the page.
ICNF declared the fire extinguished on 27 August 2025. Satellites may still see smouldering spots afterwards.
Alert according to ICNF: 26 August 2025 at 15:32. Official cause: rekindling.
First day with fire on the page (satellite or perimeter): 25 August 2025.
VIIRS detections at 375 m. Most intense hotspot: 4 MW.
There is no official record to compare with. Each hotspot is a pixel detected in one satellite pass, not a separate fire.
Total radiative power on 27 August 2025; hotspots that day: 5.
Fire radiative power (FRP) measures the energy the fire gives off when the satellite passes. Added up by day, it compares intensity, not area.
Fire Weather Index (Canadian system) computed by WorldFires for the day the fire started. Consecutive days without rain before: 35.
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
High of 25.6 °C and minimum humidity of 51% on 25 August 2025; gusts of 38 km/h on 26 August 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.
Every night a snapshot of what the page shows is saved. If anything changes, it appears in the list as a log entry.
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.
| fecha | focos_viirs | frp_mw | tmax_c | tmin_c | hr_min_pct | viento_max_kmh | racha_max_kmh | precip_mm | fwi | clase_fwi | dentro_del_incendio |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2025-08-25 | 0 | 0 | 25.6 | 15.1 | 51 | 10.9 | 30.2 | 0 | 27.9 | alto | 1 |
| 2025-08-26 | 0 | 0 | 25.3 | 11.5 | 43 | 13.8 | 38.5 | 0 | 27.1 | alto | 1 |
| 2025-08-27 | 5 | 12 | 19.5 | 10 | 58 | 15.4 | 38.5 | 0.4 | 26.9 | alto | 1 |
| 2025-08-28 | 0 | 0 | 19.4 | 9.1 | 51 | 16.6 | 42.1 | 0.1 | 25.6 | alto | 0 |
| 2025-08-29 | 0 | 0 | 19.2 | 12.8 | 68 | 15.1 | 41.8 | 3.7 | 6.9 | bajo | 0 |
It is generated in your browser from this page’s data: one file per fire, aggregated by day and without individual hotspots.
It updates itself while the fire is still active and links to this page. Free, with the attribution shown at the bottom.
Sources for this page: EFFIS (Copernicus), NASA FIRMS (VIIRS), ICNF, ERA5 (ECMWF/Copernicus C3S) · Open-Meteo.com (CC BY 4.0), GHSL (JRC). Open-Meteo.com · How we build fire pages: methodology
27 Aug 2025 · 12 MW · 5
Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.
It had gone 35 days without rain (1 mm or more) when it started. Rain came after the fire: 3.7 mm on 29 Aug.
100% of the perimeter overlaps earlier fires recorded since 2016: 218 ha in 2016, 100 ha in 2022, 1 ha in 2023, 46 ha in 2024. Part of it burned more than once, so the yearly figures add up to more than the 218 ha that had burned before.
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.
Land cover inside the perimeter according to Corine Land Cover, as reported by Copernicus.
Inside the perimeter there was no noticeable built-up land and almost nobody lived there (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
According to ICNF, 2 fires started inside this perimeter on these dates, totalling 221 ha (the satellite measured 218 ha).
ICNF records each fire that started at a different time or place separately; the satellite sees a single burned area, so this page groups them together. The numbers on the map show where each one started.
Total according to ICNF: 221 ha, 101 % of the 218 ha in the satellite perimeter.
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.
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) |
|---|---|---|---|---|---|
| 25 Aug | 25.6 °C | 51 % | 30 km/h | 0.0 mm | High 28 |
| 26 Aug | 25.3 °C | 43 % | 38 km/h | 0.0 mm | High 27 |
| 27 Aug | 19.5 °C | 58 % | 38 km/h | 0.4 mm | High 27 |
| 28 Aug after | 19.4 °C | 51 % | 42 km/h | 0.1 mm | High 26 |
| 29 Aug after | 19.2 °C | 68 % | 42 km/h | 3.7 mm | Low 7 |
It started with an FWI of 27.9, a minimum humidity of 51% and 35 days without rain. Fires in the area that started in weather like this since 2016: 22.
First rain (1 mm or more) after it ended: 2.3 mm on 12 Aug.
First rain (1 mm or more) after it ended: 1.6 mm on 16 Aug.
First rain (1 mm or more) after it ended: 3.3 mm on 24 Aug.
First rain (1 mm or more) after it ended: 2.6 mm on 16 Aug.
First rain (1 mm or more) after it ended: 4.4 mm on 15 Aug.
It burned an area similar to its twins (218 ha against a median of 164 ha) and lasted 3 days, against 2 days.
In 2 of 22, not even 1 mm fell in the ten days after the end: they went out without rain. In the rest, the first rainy day brought a median of 3.2 mm.
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
It was considered over on 27 Aug, and on 29 Aug 3.7 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 20 of 22, with a median of 3.2 mm.
Weather on this page: Open-Meteo.com (CC BY 4.0) · Copernicus Climate Change Service (ERA5)
Drag the line to compare the same ground before the fire and after it.
If the day is cloudy, change the date: each satellite passes once a day. In false colour the burnt ground looks brown or red.
On 24 August 2025 the air beside the fire reached 18 µg/m³ of PM2.5, but no daily average passed the WHO guideline (15).
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)
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
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
No changes since 24 October 2026.
RSS Changes to this page With cross-checks and a citable version
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.
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.