Montalegre fire, 17 March 2026
Meixedo e Padornelos, Sarraquinhos, Gralhas
Out · last detection 17 Mar 2026, 13:48 UTC
The fire started on 17 March 2026 in Meixedo e Padornelos, Portugal, and satellites saw it burning for 19 days. Copernicus mapped a burnt perimeter of 247 hectares from satellite imagery, spread across 4 freguesias. According to ICNF, the largest of the 2 recorded fires was detected on 17 March 2026 at 12:14 and declared extinguished on 17 March 2026.
It is the 19th largest in Montalegre since 2016 (of 65 with a page). Number 38 in Portugal in 2026, of 87.
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
19.5°C · 34% RH
High of 19.5 °C and minimum humidity of 34% on 4 April 2026; gusts of 50 km/h on 18 March 2026.
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
· reconstructedweather
Weather and FWI computed from the ERA5 reanalysis
· reconstructedofficial
Matched with the official ICNF record
Matches: 299 ha in the official record (records: 2).
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.
What burned
Other natural land95 %
Broadleaved forest5.2 %
Land cover inside the perimeter according to Corine Land Cover, as reported by Copernicus.
Official record
Complex of 2 fires according to ICNF
According to ICNF, 2 fires started inside this perimeter on these dates, totalling 299 ha (the satellite measured 247 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.
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)
17 Mar
16.6 °C
29 %
44 km/h
0.0 mm
Very low 2
18 Mar
13.3 °C
50 %
50 km/h
0.2 mm
Very low 2
19 Mar
16.8 °C
40 %
37 km/h
0.7 mm
Very low 2
20 Mar
11.8 °C
65 %
28 km/h
2.4 mm
Very low 0
21 Mar
13.9 °C
50 %
31 km/h
0.0 mm
Very low 0
22 Mar
15.5 °C
48 %
17 km/h
0.4 mm
Very low 1
23 Mar
14.7 °C
39 %
31 km/h
0.0 mm
Very low 2
24 Mar
16.2 °C
33 %
22 km/h
0.0 mm
Very low 3
25 Mar
15.0 °C
50 %
37 km/h
0.0 mm
Very low 4
26 Mar
14.0 °C
41 %
40 km/h
0.0 mm
Very low 5
27 Mar
14.7 °C
45 %
28 km/h
0.0 mm
Very low 4
28 Mar
14.9 °C
39 %
43 km/h
0.0 mm
Low 6
29 Mar
12.3 °C
36 %
47 km/h
0.0 mm
Low 6
30 Mar
15.7 °C
42 %
40 km/h
0.0 mm
Low 5
31 Mar
18.5 °C
40 %
27 km/h
0.0 mm
Low 6
1 Apr
17.2 °C
36 %
33 km/h
0.0 mm
Low 7
2 Apr
15.2 °C
41 %
40 km/h
0.0 mm
Low 8
3 Apr
18.2 °C
30 %
22 km/h
0.0 mm
Low 7
4 Apr
19.5 °C
34 %
33 km/h
0.0 mm
Low 9
5 Apr after
20.9 °C
30 %
32 km/h
0.0 mm
Low 10
6 Apr after
22.2 °C
17 %
53 km/h
1.9 mm
Low 9
Its twins: fires that started in the same weather
It started with an FWI of 2.3, a minimum humidity of 29% and 2 days without rain. Fires in the area that started in weather like this since 2016: 19.
FWI at the start2.3
Minimum humidity29 %
Days without rain2
this firechosen twinsrest of the area
Almost identicalSimilar
Outlines of the closest twins
This fire · Montalegre fire, 17 March 2026
247 ha19 daysFWI 2.3Min. humidity 29 %
Montalegre fire, March 2020
153 ha2 daysFWI 2.6Min. humidity 26 %3 km away, in 2020
First rain (1 mm or more) after it ended: 7.8 mm on 31 Mar.
It was 1.5 times larger than the median of its twins and lasted 19 days, against 2 days.
Only 4 of its 19 twins burned more. The weather on the first day does not explain everything: the wind in the following days, the fuel and the firefighting also count. In 4 of 19, 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 4.4 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
How it ended
1.9 mmfirst rain
6 Apr2 days after it ended
50km/h · max. gust
It was considered over on 4 Apr, and on 6 Apr 1.9 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 15 of 19, with a median of 4.4 mm.
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 · 10 Mar 2026
After · 11 Apr 2026
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 19 March 2026 the air beside the fire reached 23 µg/m³ of PM2.5, but no daily average passed the WHO guideline (15).
PM2.5 peak23µg/m³
Days over the guideline0days
PM1038µg/m³
Optical depth0.24
WHO 15
15 Mar17 Mar19 Mar
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· 4Every 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.
The official perimeter only gives the start date (17 March 2026). The end comes from the heat detections inside the perimeter: it burned until 4 April 2026 (19 days from 17 March 2026), the last day with detections before more than 10 days in a row without any, so it is approximate. According to ICNF, the largest of the 2 recorded fires was detected on 17 March 2026 at 12:14 and declared extinguished on 17 March 2026.
How much area did it burn?
The perimeter Copernicus measured from satellite imagery is 247 hectares (2.5 km²). Official national figures may differ.
Which freguesias burned?
The fire entered 4 freguesias: Meixedo e Padornelos (179 ha, 5.0 %); Sarraquinhos (31 ha, 0.9 %); Gralhas (30 ha, 1.4 %); Chã (7 ha, 0.1 %).
Did the fire reach a town?
The fire came within 1.6 km of the centre of Gralhas, 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 19.5 °C, humidity dropped to 29 % and gusts hit 50 km/h. The fire danger index (FWI) reached 9, 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.
How did the fires that started in similar weather in this area end?
Fires less than 250 km away that started since 2016 with a similar FWI, humidity and dry spell: 19. Their median duration was 2 days and their median area 160 ha; 0 % went past 1,000 ha. Only 4 of its 19 twins burned more. The weather on the first day does not explain everything: the wind in the following days, the fuel and the firefighting also count. In 4 of 19, 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 4.4 mm.
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.
The official perimeter has no end date: the end is the last day with VIIRS detections inside the perimeter before a gap of more than 10 days (150 days at most), so it is approximate. 4 Suomi-NPP VIIRS detections on those dates.
Compared with ICNF: 299 official ha against 247 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.