How long did the Tendais fire last?

According to the heat detections seen by satellite inside the perimeter, it burned from 4 October 2017 to 8 October 2017 (5 days). The perimeter dates it from 4 October 2017 to 7 October 2017. According to ICNF, the largest of the 5 recorded fires was detected on 3 October 2017 at 23:49 and declared extinguished on 4 October 2017.

How much area did it burn?

The perimeter Copernicus measured from satellite imagery is 299 hectares (3.0 km²). Official national figures may differ.

Which municipalities burned?

The fire entered 2 municipalities: Tendais (296 ha, 9.3 %); Cabril (4 ha, 0.2 %).

Did the fire reach a town?

The fire started in Tendais and came within 1.2 km of its centre. 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 24.4 °C, humidity dropped to 13 % and gusts hit 44 km/h. The fire danger index (FWI) reached 31, 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.

PT · Portugal · 2017-10-04 → 2017-10-08

Tendais fire, 4 October 2017 Tendais, Cabril

Out · last detection 8 Oct 2017, 02:06 UTC

The fire started on 4 October 2017 in Tendais, Portugal, and satellites saw it burning for 5 days. Copernicus mapped a burnt perimeter of 299 hectares from satellite imagery, spread across 2 municipalities. According to ICNF, the largest of the 5 recorded fires was detected on 3 October 2017 at 23:49 and declared extinguished on 4 October 2017.

It is the 13th largest in Cinfães since 2016 (of 31 with a page). Number 120 in Portugal in 2017, of 211.

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Burnt area: 299ha; Copernicus perimeter
Duration: 5days; 4 Oct 2017 – 8 Oct 2017
Municipalities hit: 2; freguesias
Started on: 4 Oct; 2017
Heat detections: 38; in a single hotspot: 39 MW
Danger at start: 18; Moderate · FWI index
Average daily power: 108MW; detected power per day, on average

HOTSPOTS BY DAY 4 Oct8 Oct

Play back 8 Oct 2017

How it evolved, day by day

4 Oct 5 Oct 6 Oct 7 Oct 8 Oct

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

44km/h · peak gust

13%lowest humidity

It had gone 34 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

No earlier perimeters overlap this fire since 2016, when the satellite record begins.

What happened to each town

Tendais 697 inhabitants · 1.2 km from the centre where it started

296 ha reached on 4 Oct

9.3 %
Cabril 3.4 km from the centre

4 ha

0.2 %

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 land96 %
Scrub and transitional woodland3.6 %

Natura 2000 protected area affected: 100 %

LIC Serra de Montemuro PTCON0025

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

Complex of 5 fires according to ICNF

According to ICNF, 5 fires started inside this perimeter on these dates, totalling 284 ha (the satellite measured 299 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.

When each one burned

1 12 ha 2 7 ha 3 131 ha 4 126 ha 5 7 ha

2 Oct9 Oct

negligence arson rekindling

1 Cinfães Bustelo 2 October 2017 · 15:22 12 ha · extinguished on 2 October 2017 · cause: negligence
2 Cinfães Bustelo 3 October 2017 · 15:03 7 ha · extinguished on 3 October 2017 · cause: negligence
3 Cinfães Tendais 3 October 2017 · 23:49 131 ha · extinguished on 4 October 2017 · cause: arson
4 Cinfães Tendais 4 October 2017 · 15:19 126 ha · extinguished on 4 October 2017 · cause: rekindling
5 Cinfães Bustelo 8 October 2017 · 14:52 7 ha · extinguished on 8 October 2017 · cause: negligence

Total according to ICNF: 284 ha, 95 % of the 299 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)
4 Oct	24.4 °C	36 %	24 km/h	0.0 mm	Moderate 18
5 Oct	23.8 °C	32 %	24 km/h	0.0 mm	Moderate 18
6 Oct	24.4 °C	26 %	28 km/h	0.0 mm	High 22
7 Oct	23.4 °C	13 %	44 km/h	0.0 mm	High 31
8 Oct	24.2 °C	15 %	25 km/h	0.0 mm	High 29
9 Oct after	22.6 °C	22 %	22 km/h	0.0 mm	High 28
10 Oct after	22.5 °C	21 %	18 km/h	0.0 mm	High 27
11 Oct after	21.4 °C	21 %	29 km/h	0.0 mm	High 29
12 Oct after	23.9 °C	26 %	27 km/h	0.0 mm	High 27
13 Oct after	21.1 °C	37 %	19 km/h	0.0 mm	High 22
14 Oct after	24.9 °C	27 %	30 km/h	0.0 mm	High 25
15 Oct after	27.6 °C	20 %	64 km/h	0.7 mm	High 35
16 Oct after	19.3 °C	36 %	42 km/h	0.9 mm	Moderate 17
17 Oct after	14.9 °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 · 27 Sept 2017

After · 15 Oct 2017

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.

The smoke

CAMS · Copernicus

On 16 October 2017 the air beside the fire reached 363 µg/m³ of PM2.5. That day averaged 141: 9.4 times the WHO daily guideline (15).

PM2.5 peak363 µg/m³

Days over the guideline10 days

PM10389 µg/m³

WHO 15

23456789101112131415161718

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 · 38Every 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

All fires in Portugal ›

Frequently asked questions

How long did the Tendais fire last?: According to the heat detections seen by satellite inside the perimeter, it burned from 4 October 2017 to 8 October 2017 (5 days). The perimeter dates it from 4 October 2017 to 7 October 2017. According to ICNF, the largest of the 5 recorded fires was detected on 3 October 2017 at 23:49 and declared extinguished on 4 October 2017.
How much area did it burn?: The perimeter Copernicus measured from satellite imagery is 299 hectares (3.0 km²). Official national figures may differ.
Which municipalities burned?: The fire entered 2 municipalities: Tendais (296 ha, 9.3 %); Cabril (4 ha, 0.2 %).
Did the fire reach a town?: The fire started in Tendais and came within 1.2 km of its centre. 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 24.4 °C, humidity dropped to 13 % and gusts hit 44 km/h. The fire danger index (FWI) reached 31, 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

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.

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.

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What do you think is wrong?

Dates or duration Place or towns Burned area Name It was not a wildfire Same fire as another page Something else

What really happened?

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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 adjusted with the VIIRS detections inside the perimeter, which said 4 October 2017 to 7 October 2017. 38 Suomi-NPP VIIRS detections on those dates.
Compared with ICNF: 284 official ha against 299 ha of perimeter; they agree within 25%.
Weather: Copernicus ERA5 reanalysis at the fire location, in cells of about 25 km.

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