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Tendais fire, 15 October 2017 Ferreiros de Tendais, Alhões, Bustelo, Gralheira e Ramires, Oliveira do Douro

Out · last detection 15 Oct 2017, 12:58 UTC

The fire started on 15 October 2017 in Tendais, Portugal, and satellites saw it burning for 1 day. Copernicus mapped a burnt perimeter of 887 hectares from satellite imagery, spread across 4 municipalities.

It is the 5th largest in Cinfães since 2016 (of 31 with a page). Number 65 in Portugal in 2017, of 211.

The power measured by the satellite is low (17.2 MW in the strongest hotspot), more typical of grass or stubble burning, or a slow surface fire, than of a large crown fire.

Compare with…

Suggestions: Cinfães · 2016Cinfães · 2016União das Freguesias de Campelo e Ovil e Loivos do Monte · 2024Castro Daire · 2024

Burnt area
887ha
Copernicus perimeter
Duration
1day
15 Oct 2017 – 15 Oct 2017
Municipalities hit
4
freguesias
Started on
15 Oct
2017
Heat detections
3
in a single hotspot: 17 MW
Danger at start
35
High · FWI index
Average daily power
36MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 15 Oct15 Oct

How it evolved, day by day

15 Oct 2017 · 36 MW · 3

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

The weather it burned in

29°high
64km/h · peak gust
21%lowest humidity

It had gone 45 days without rain (1 mm or more) when it started. Rain came after the fire: 23.4 mm on 17 Oct.

This area had burned before

43% of the perimeter overlaps earlier fires recorded since 2016: 385 ha in 2016.

How big is it?

10 km
It burned the equivalent of 0.6% of the area of London (8.9 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

  1. Ferreiros de Tendais 540 inhabitants · 1.1 km from the centre
    434 ha reached on 15 Oct
    27 %
  2. Alhões, Bustelo, Gralheira e Ramires 517 inhabitants · 3.5 km from the centre
    354 ha
    9.4 %
  3. Oliveira do Douro 1,257 inhabitants · 2.8 km from the centre
    53 ha
    3.7 %
  4. Tendais 697 inhabitants · 2.6 km from the centre where it started
    47 ha reached on 15 Oct
    1.5 %

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 land89 %
  • Agricultural areas6.0 %
  • Scrub and transitional woodland4.6 %

Natura 2000 protected area affected: 97 %

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.

People and buildings inside the perimeter

GHSL 2015
Built-up area0.20 ha
Residents< 20

Inside the perimeter there were about 0.20 hectares of built-up land and almost nobody lived there (GHSL 2015, 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

Several official records match this area

According to ICNF, 3 fires started inside this perimeter on these dates, totalling 306 ha (the satellite measured 887 ha). The two figures differ a lot, so these may not be exactly the same fire: take them as nearby records.

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.

When each one burned

1 190 ha 2 19 ha 3 96 ha
12 Oct17 Oct
cause unknown or not published arson
  1. 1 Cinfães Bustelo 12 October 2017 · 16:02 190 ha · extinguished on 12 October 2017 · cause: unknown
  2. 2 Resende Panchorra 12 October 2017 · 18:14 19 ha · extinguished on 12 October 2017 · cause: unknown
  3. 3 Cinfães Bustelo 15 October 2017 · 02:25 96 ha · extinguished on 17 October 2017 · cause: arson

Total according to ICNF: 306 ha, 34 % of the 887 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.

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)
15 Oct 29.2 °C 21 % 64 km/h 0.7 mm High 35
16 Oct after 20.9 °C 37 % 42 km/h 0.9 mm Moderate 17
17 Oct after 16.5 °C 48 % 45 km/h 23.4 mm Very low 0

Before and after, from space

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

Before · 8 Oct 2017
After · 22 Oct 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.

Detections table · 3Every 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 Tendais fire last?
Copernicus dates it between 15 October 2017 and 15 October 2017: 1 day between the first and last image with fire.
How much area did it burn?
The perimeter Copernicus measured from satellite imagery is 887 hectares (8.9 km²). Official national figures may differ.
Which municipalities burned?
The fire entered 4 municipalities: Ferreiros de Tendais (434 ha, 27 %); Alhões, Bustelo, Gralheira e Ramires (354 ha, 9.4 %); Oliveira do Douro (53 ha, 3.7 %); Tendais (47 ha, 1.5 %).
Did the fire reach a town?
The fire came within 1.1 km of the centre of Ferreiros de Tendais, 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 29.2 °C, humidity dropped to 21 % and gusts hit 64 km/h. The fire danger index (FWI) reached 35, class 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

History of this page · 1 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.
  1. Matched to the official record from ICNF.

RSS Changes to this page

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.

How we know this
  • Perimeter: EFFIS (Copernicus), mapped on satellite imagery.
  • Dates from the perimeter: the VIIRS detections inside it did not change them. 3 Suomi-NPP VIIRS detections on those dates.
  • Compared with ICNF: 306 official ha against 887 ha of perimeter; similar, but with reservations.
  • 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 2015, 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.