Seia fire, March 2021 União das Freguesias de Vide e Cabeça, Sazes da Beira, Loriga
The fire started on 18 March 2021 in União das Freguesias de Vide e Cabeça, Portugal, and satellites saw it burning for 1 day. Copernicus mapped a burnt perimeter of 330 hectares from satellite imagery, spread across 3 municipalities. According to ICNF, it was detected on 17 March 2021 at 23:27 and declared extinguished on 22 March 2021.
Number 7 in Portugal in 2021, of 30.
Compare with…
- Burnt area
- 330ha
- Copernicus perimeter
- Duration
- 1day
- 18 Mar 2021 – 18 Mar 2021
- Municipalities hit
- 3
- freguesias
- Started on
- 18 Mar
- 2021
- Heat detections
- 18
- in a single hotspot: 44 MW
- Danger at start
- 8
- Low · FWI index
- Average daily power
- 370MW
- detected power per day, on average
Where it burned
How it evolved, day by day
18 Mar 2021 · 370 MW · 18
Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.
The weather it burned in
It had gone 12 days without rain (1 mm or more) when it started.
This area had burned before
No earlier perimeters overlap this fire since 2016, when the satellite record begins.
What happened to each town
-
283 ha reached on 18 Mar5.0 %
-
Sazes da Beira 245 inhabitants · 1.2 km from the centre43 ha reached on 18 Mar5.6 %
-
Loriga 848 inhabitants · 3.4 km from the centre5 ha reached on 18 Mar0.1 %
Burnt area inside each municipality, 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
- Coniferous forest58 %
- Scrub and transitional woodland42 %
Natura 2000 protected area affected: 100 %
- LIC Serra da Estrela PTCON0014
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 17 March 2021 and burned 350 ha (the satellite measured 330 ha).
- Seia Loriga 17 March 2021 · 23:27 350 ha · extinguished on 22 March 2021 · cause: negligence
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)
| Day | High | Min. humidity | Peak gust | Rain | Danger (FWI) |
|---|---|---|---|---|---|
| 18 Mar | 12.6 °C | 35 % | 53 km/h | 0.0 mm | Low 8 |
| 19 Mar after | 12.8 °C | 43 % | 42 km/h | 0.0 mm | Low 7 |
| 20 Mar after | 9.8 °C | 34 % | 59 km/h | 0.0 mm | Low 9 |
| 21 Mar after | 12.6 °C | 37 % | 45 km/h | 0.0 mm | Low 7 |
| 22 Mar after | 15.4 °C | 33 % | 30 km/h | 0.0 mm | Low 7 |
| 23 Mar after | 16.9 °C | 29 % | 27 km/h | 0.0 mm | Low 8 |
| 24 Mar after | 15.3 °C | 45 % | 29 km/h | 0.0 mm | Low 7 |
| 25 Mar after | 14.5 °C | 40 % | 26 km/h | 0.0 mm | Low 7 |
| 26 Mar after | 12.2 °C | 54 % | 39 km/h | 0.0 mm | Low 7 |
| 27 Mar after | 15.1 °C | 35 % | 30 km/h | 0.0 mm | Low 7 |
| 28 Mar after | 19.0 °C | 36 % | 36 km/h | 0.0 mm | Low 8 |
Before and after, from space
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.
The smoke
CAMS · CopernicusOn 16 March 2021 the air beside the fire reached 11 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)
Detections table · 18Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
- 19,125 haSeia Pamos Da SerraOctober 2017 · 8 days · 18 km away
- 68,190 haArganil Sobral de São MiguelAugust 2025 · 15 days · 23 km away
- 25,260 haSerra da Estrela SameiroAugust 2022 · 18 days · 24 km away
- 8,372 haPampilhosa da Serra Fajão-VidualOctober 2017 · 4 days · 24 km away
- 132,830 haPombeiro da BeiraOctober 2017 · 10 days · 29 km away
- 8,554 haPenalva do Castelo Vila Cova do Covelo/MarecoSeptember 2024 · 5 days · 35 km away
Frequently asked questions
- How long did the Seia fire last?
- Copernicus dates it between 18 March 2021 and 18 March 2021: 1 day between the first and last image with fire. According to ICNF, it was detected on 17 March 2021 at 23:27 and declared extinguished on 22 March 2021.
- How much area did it burn?
- The perimeter Copernicus measured from satellite imagery is 330 hectares (3.3 km²). Official national figures may differ.
- Which municipalities burned?
- The fire entered 3 municipalities: União das Freguesias de Vide e Cabeça (283 ha, 5.0 %); Sazes da Beira (43 ha, 5.6 %); Loriga (5 ha, 0.1 %).
- Did the fire reach a town?
- The fire came within 1.2 km of the centre of Sazes da Beira, 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 12.6 °C, humidity dropped to 35 % and gusts hit 53 km/h. The fire danger index (FWI) reached 8, class Low.
- 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 ›
- ICNF · Instituto da Conservação da Natureza e das Florestas ↗
- ANEPC · Proteção Civil ↗
- Fogos.pt (ocorrências em tempo real) ↗
Satellite cross-check
History of this page Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.
No changes 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
How we know this
- Perimeter: EFFIS (Copernicus), mapped on satellite imagery.
- Dates from the perimeter: the VIIRS detections inside it did not change them. 18 Suomi-NPP VIIRS detections on those dates.
- Compared with ICNF: 350 official ha against 330 ha of perimeter; they agree within 25%.
- Weather: Copernicus ERA5 reanalysis at the fire location, in cells of about 25 km.
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. Municipal boundaries come from geoBoundaries ADM3 (CC0 1.0 Universal (CC0 1.0) Public Domain Dedication). The area per municipality is computed by WorldFires by crossing the perimeter with those boundaries, so it may differ slightly from each country’s official figure.