How long did the Alijó fire last?

Copernicus dates it between 6 August 2020 and 8 August 2020: 3 days between the first and last image with fire. According to ICNF, it was detected on 6 August 2020 at 12:06 and declared extinguished on 8 August 2020.

How much area did it burn?

The perimeter Copernicus measured from satellite imagery is 949 hectares (9.5 km²). Official national figures may differ.

Which municipalities burned?

The fire entered 3 municipalities: União das Freguesias de Carlão e Amieiro (538 ha, 16 %); Alijó (411 ha, 14 %); Vila Chã (1 ha, 0.0 %).

Did the fire reach a town?

The fire came within 0.9 km of the centre of União das Freguesias de Carlão e Amieiro, 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 35.1 °C, humidity dropped to 23 % and gusts hit 39 km/h. The fire danger index (FWI) reached 40, class Very high.

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.

PT · Portugal · 2020-08-06 → 2020-08-08

Alijó fire, August 2020 União das Freguesias de Carlão e Amieiro, Alijó, Vila Chã

Out · last detection 8 Aug 2020, 01:59 UTC

The fire started on 6 August 2020 in Alijó, Portugal, and satellites saw it burning for 3 days. Copernicus mapped a burnt perimeter of 949 hectares from satellite imagery, spread across 3 municipalities. According to ICNF, it was detected on 6 August 2020 at 12:06 and declared extinguished on 8 August 2020.

It is the 4th largest in Alijó since 2016 (of 11 with a page). Number 12 in Portugal in 2020, of 67.

Compare with…

Suggestions: Alijó · 2017 Murça · 2022 Vila Pouca de Aguiar · 2024 Vila Real · 2022

Burnt area: 949ha; Copernicus perimeter
Duration: 3days; 6 Aug 2020 – 8 Aug 2020
Municipalities hit: 3; freguesias
Started on: 6 Aug; 2020
Heat detections: 33; in a single hotspot: 35 MW
Danger at start: 40; Very high · FWI index
Average daily power: 67MW; detected power per day, on average

HOTSPOTS BY DAY 6 Aug8 Aug

Play back 8 Aug 2020

How it evolved, day by day

6 Aug 7 Aug 8 Aug

Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.

The weather it burned in

35°high

39km/h · peak gust

23%lowest humidity

It had gone 15 days without rain (1 mm or more) when it started. Rain came after the fire: 1.3 mm on 17 Aug.

This area had burned before

99% of the perimeter overlaps earlier fires recorded since 2016: 942 ha in 2017.

942 ha Alijó fire, July 2017 5,597 ha in total; the hectares shown are those it shares with this fire

How big is it?

It burned the equivalent of 0.6% of the area of London (9.5 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 town

União das Freguesias de Carlão e Amieiro 627 inhabitants · 0.9 km from the centre

538 ha reached on 7 Aug

16 %
Alijó 2,584 inhabitants · 2.2 km from the centre where it started

411 ha reached on 6 Aug

14 %
Vila Chã 2.5 km from the centre

1 ha

0.0 %

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

Other natural land86 %
Agricultural areas14 %

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

People and buildings inside the perimeter

GHSL 2020

Built-up area1.4 ha

Residents< 20

Inside the perimeter there were about 1.4 hectares of built-up land and almost nobody lived there (GHSL 2020, 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.

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

Official record

According to ICNF, this fire started on 6 August 2020 and burned 973 ha (the satellite measured 949 ha).

Alijó Alijó 6 August 2020 · 12:06 973 ha · extinguished on 8 August 2020 · 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)
6 Aug	35.1 °C	23 %	39 km/h	0.0 mm	Very high 40
7 Aug	32.1 °C	34 %	32 km/h	0.0 mm	High 35
8 Aug	31.6 °C	27 %	39 km/h	0.0 mm	High 35
9 Aug after	29.9 °C	32 %	35 km/h	0.0 mm	High 36
10 Aug after	28.3 °C	41 %	30 km/h	0.0 mm	High 30
11 Aug after	27.8 °C	30 %	38 km/h	0.2 mm	High 30
12 Aug after	22.3 °C	57 %	35 km/h	0.5 mm	High 23
13 Aug after	26.4 °C	34 %	30 km/h	0.0 mm	High 26
14 Aug after	26.8 °C	33 %	38 km/h	0.0 mm	High 31
15 Aug after	22.4 °C	39 %	44 km/h	0.0 mm	High 31
16 Aug after	22.0 °C	47 %	42 km/h	0.0 mm	High 27
17 Aug after	21.8 °C	59 %	50 km/h	1.3 mm	Low 11

Before and after, from space

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

↔

Before · 30 Jul 2020

After · 15 Aug 2020

Before After

If the day is cloudy, change the date: each satellite passes once a day. In false colour the burnt ground looks brown or red.

Detections table · 33Every 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 time	Satellite	FRP (MW)	Lat	Lon

Other fires nearby

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Frequently asked questions

How long did the Alijó fire last?: Copernicus dates it between 6 August 2020 and 8 August 2020: 3 days between the first and last image with fire. According to ICNF, it was detected on 6 August 2020 at 12:06 and declared extinguished on 8 August 2020.
How much area did it burn?: The perimeter Copernicus measured from satellite imagery is 949 hectares (9.5 km²). Official national figures may differ.
Which municipalities burned?: The fire entered 3 municipalities: União das Freguesias de Carlão e Amieiro (538 ha, 16 %); Alijó (411 ha, 14 %); Vila Chã (1 ha, 0.0 %).
Did the fire reach a town?: The fire came within 0.9 km of the centre of União das Freguesias de Carlão e Amieiro, 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 35.1 °C, humidity dropped to 23 % and gusts hit 39 km/h. The fire danger index (FWI) reached 40, class Very high.
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

NASA FIRMS ↗
EFFIS · Copernicus ↗

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.

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How we know this

Perimeter: EFFIS (Copernicus), mapped on satellite imagery.
Dates from the perimeter: the VIIRS detections inside it did not change them. 33 Suomi-NPP VIIRS detections on those dates.
Compared with ICNF: 973 official ha against 949 ha of perimeter; they agree within 25%.
Weather: Copernicus ERA5 reanalysis at the fire location, in cells of about 25 km.
Built-up area and population come from the JRC Global Human Settlement Layer (epoch 2020, 100 m cells), summed inside the perimeter: an estimate of what was there, not a damage count.

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. 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.

Where it burned