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Sertã fire, September 2017 Sertã, Várzea dos Cavaleiros, Proença a Nova e Peral

Out · last detection 10 Sept 2017, 02:31 UTC

The fire started on 9 September 2017 in Sertã, Portugal, and satellites saw it burning for 2 days. Copernicus mapped a burnt perimeter of 3,966 hectares from satellite imagery, spread across 7 municipalities. According to ICNF, it was detected on 8 September 2017 at 17:35 and declared extinguished on 11 September 2017.

Number 22 in Portugal in 2017, of 210.

Burnt area
3,966ha
Copernicus perimeter
Duration
2days
9 Sept 2017 – 10 Sept 2017
Municipalities hit
7
freguesias
Started on
9 Sept
2017
Heat detections
109
in a single hotspot: 107 MW
Danger at start
50
Very high · FWI index
Energy released
1.5GW
sum of detected power

Where it burned

10 Sept 2017
HOTSPOTS BY DAY 9 Sept10 Sept

How it evolved, day by day

910

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

The weather it burned in

24°high
61km/h · peak gust
31%lowest humidity

It had gone 10 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

  1. Sertã 6,039 inhabitants · 2.1 km from the town where it started
    2,338 ha reached on 9 Sept
    29 %
  2. Várzea dos Cavaleiros 627 inhabitants · 0.0 km from the town
    1,141 ha reached on 9 Sept
    33 %
  3. Proença a Nova e Peral 4,498 inhabitants · 8.6 km from the town
    394 ha
    2.3 %
  4. Carvalhal 1.3 km from the town
    86 ha
    8.7 %
  5. Ermida e Figueiredo 338 inhabitants · 3.7 km from the town
    5 ha
    0.1 %
  6. Cumeada e Marmeleiro 659 inhabitants · 4.6 km from the town
    4 ha reached on 10 Sept
    0.1 %
  7. Pedrógão Pequeno 706 inhabitants · 2.3 km from the town
    2 ha
    0.1 %

Burnt area inside each municipality, from crossing the official perimeter with administrative boundaries. The distance is from the town centre to the nearest fire: staying a kilometre away does not mean it reached the houses.

What burned

  • Scrub and transitional woodland54 %
  • Mixed forest18 %
  • Coniferous forest18 %
  • Agricultural areas10.0 %

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

Official record

According to ICNF, this fire started on 8 September 2017 and burned 3,878 ha (the satellite measured 3,966 ha).

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)
9 Sept 21.3 °C 44 % 61 km/h 0.0 mm Very high 50
10 Sept 24.3 °C 31 % 45 km/h 0.0 mm High 30
11 Sept after 27.0 °C 39 % 45 km/h 0.0 mm High 35
12 Sept after 27.1 °C 36 % 40 km/h 0.0 mm High 36
13 Sept after 29.8 °C 37 % 40 km/h 0.0 mm High 30
14 Sept after 26.9 °C 42 % 46 km/h 0.0 mm Very high 40
15 Sept after 22.6 °C 25 % 49 km/h 0.0 mm Very high 42
16 Sept after 22.3 °C 26 % 41 km/h 0.0 mm High 37
17 Sept after 22.0 °C 32 % 40 km/h 0.0 mm High 34
18 Sept after 23.5 °C 42 % 42 km/h 0.0 mm High 28
19 Sept after 26.8 °C 35 % 31 km/h 0.0 mm High 22
20 Sept after 27.6 °C 33 % 30 km/h 0.0 mm High 30

Before and after, from space

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

Before · 2 Sept 2017
After · 17 Sept 2017

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 9 September 2017 the air beside the fire reached 20 µg/m³ of PM2.5. That day averaged 15: 1.0 times the WHO daily guideline (15).

PM2.5 peak20 µg/m³
Days over the guideline1 day
PM1027 µg/m³
789101112131415161718
Good Fair Moderate Poor Very poor Extremely 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 · 109Every 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 timeSatelliteFRP (MW)LatLon

Other fires nearby

All fires in Portugal ›

Frequently asked questions

How long did the Sertã fire last?
Copernicus dates it between 9 September 2017 and 10 September 2017: 2 days between the first and last image with fire. According to ICNF, it was detected on 8 September 2017 at 17:35 and declared extinguished on 11 September 2017.
How much area did it burn?
The perimeter Copernicus measured from satellite imagery is 3,966 hectares (39.7 km²). Official national figures may differ.
Which municipalities burned?
The fire entered 7 municipalities: Sertã (2,338 ha, 29 %); Várzea dos Cavaleiros (1,141 ha, 33 %); Proença a Nova e Peral (394 ha, 2.3 %); Carvalhal (86 ha, 8.7 %); Ermida e Figueiredo (5 ha, 0.1 %); Cumeada e Marmeleiro (4 ha, 0.1 %); Pedrógão Pequeno (2 ha, 0.1 %).
Did the fire reach a town?
The closest fire to a town centre came within 0.0 km of Várzea dos Cavaleiros. That is the distance to the perimeter or nearest hotspot; it does not mean it entered the houses.
What was the weather like?
During the fire the temperature reached 24.3 °C, humidity dropped to 31 % and gusts hit 61 km/h. The fire danger index (FWI) reached 50, 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

Satellite cross-check

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
What do you think is wrong?

We will only use your email to reply about this report. Privacy. This is not an emergency service: if there is a fire now, call 112.

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.