Vila Nova de Gaia fire, October 2017
Uni3O Das Freguesias De Sandim, Olival, Lever E C, União das Freguesias de Canedo, Vale e Vila Maior
Out · last measured on 16 Oct 2017
The fire started on 16 October 2017 in Uni3O Das Freguesias De Sandim, Olival, Lever E C, Portugal, and satellites saw it burning for 1 day. Copernicus mapped a burnt perimeter of 153 hectares from satellite imagery, spread across 2 freguesias.
matches the official recordwith caveatssatellite onlymodel
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Burned area
with caveats
153ha
Perimeter published by EFFIS (Copernicus).
This page153ICNF222
Source
EFFIS (Copernicus)
Date
perimeter revised on 26 January 2022
+− cross-check
ICNF: 222 ha (matched records: 1). Difference between the page and the official record: −31.0%. Matched on 1 November 2026. The two figures differ a lot, so these may not be exactly the same fire: take them as nearby records.
Duration by satellite
satellite only
1day
16 Oct 2017 to 16 Oct 2017: first and last day with fire on the page.
Source
EFFIS (Copernicus) · NASA FIRMS · VIIRS
Date
16 Oct 2017 – 16 Oct 2017
+− cross-check
Satellites pass a few times a day and cloud or smoke can hide the fire: a lack of detections is not an official extinction. Each country’s emergency service declares a fire contained or out.
Start
satellite only
16 Oct 2017
First day with fire seen by the satellites or the perimeter.
Source
EFFIS (Copernicus) · NASA FIRMS · VIIRS
Date
16 Oct 2017
+− cross-check
The two figures differ a lot, so these may not be exactly the same fire: take them as nearby records.
Danger at the start
model
4.2FWI · very low
Fire Weather Index (Canadian system) computed by WorldFires for the day the fire started. Consecutive days without rain before: 21.
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
23.0°C · 61% RH
High of 23.0 °C and minimum humidity of 61% on 16 October 2017; gusts of 47 km/h on 16 October 2017.
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
Nearby records with very different figures: 222 ha (records: 1).
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
We have the Copernicus perimeter for this fire, but the VIIRS sensors did not capture it in enough detail: no day-by-day evolution, but the split by freguesia is there.
Burnt area
153ha
Copernicus perimeter
Duration
1day
16 Oct 2017 – 16 Oct 2017
Freguesias hit
2
freguesias
Started on
16 Oct
2017
Danger at start
4
Very low · FWI index
Where it burned
The weather it burned in
23°high
47km/h · peak gust
61%lowest humidity
It had gone 21 days without rain (1 mm or more) when it started. Rain came after the fire: 25.9 mm on 17 Oct.
This area had burned before
No earlier perimeters overlap this fire since 2016, when the satellite record begins.
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
Mixed forest81 %
Artificial surfaces14 %
Agricultural areas5.2 %
Land cover inside the perimeter according to Corine Land Cover, as reported by Copernicus.
Official record
According to ICNF, this fire started on 15 October 2017 and burned 222 ha (the satellite measured 153 ha). The two figures differ a lot, so these may not be exactly the same fire: take them as nearby records.
Vila Nova de GaiaSandim15 October 2017 · 17:46222 ha· extinguished on 17 October 2017· cause: unknown
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)
16 Oct
23.0 °C
61 %
47 km/h
9.6 mm
Very low 4
17 Oct after
20.4 °C
57 %
45 km/h
25.9 mm
Very low 1
Its twins: fires that started in the same weather
It started with an FWI of 4.2, a minimum humidity of 61% and 21 days without rain. Fires in the area that started in weather like this since 2016: 17.
FWI at the start4.2
Minimum humidity61 %
Days without rain21
this firechosen twinsrest of the area
Almost identicalSimilar
Outlines of the closest twins
This fire · Vila Nova de Gaia fire, October 2017
153 ha1 dayFWI 4.2Min. humidity 61 %
Valença fire, September 2020
494 ha1 dayFWI 4.9Min. humidity 60 %105 km away, in 2020
First rain (1 mm or more) after it ended: 20.3 mm on 17 Sept.
It burned an area similar to its twins (153 ha against a median of 213 ha) and lasted 1 day, against 1 day.
In 1 of 17, 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 3.5 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
25.9 mmfirst rain
17 Octthe day after it ended
47km/h · max. gust
It was considered over on 16 Oct, and on 17 Oct 25.9 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 16 of 17, with a median of 3.5 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 · 9 Oct 2017
After · 23 Oct 2017
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 16 October 2017 the air beside the fire reached 66 µg/m³ of PM2.5. That day averaged 34: 2.2 times the WHO daily guideline (15).
PM2.5 peak66µg/m³
Days over the guideline3days
PM10104µg/m³
WHO 15
14 Oct16 Oct18 Oct
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)
Copernicus dates it between 16 October 2017 and 16 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 153 hectares (1.5 km²). Official national figures may differ.
Which freguesias burned?
The fire entered 2 freguesias: Uni3O Das Freguesias De Sandim, Olival, Lever E C (112 ha, 3.3 %); União das Freguesias de Canedo, Vale e Vila Maior (41 ha, 1.0 %).
Did the fire reach a town?
The fire started in Uni3O Das Freguesias De Sandim, Olival, Lever E C and came within 2.2 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 23.0 °C, humidity dropped to 61 % and gusts hit 47 km/h. The fire danger index (FWI) reached 4, class Very 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: 17. Their median duration was 1 day and their median area 213 ha; 0 % went past 1,000 ha. In 1 of 17, 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 3.5 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.
Dates from the perimeter: the VIIRS detections inside it did not change them. No Suomi-NPP VIIRS detections on those dates.
Compared with ICNF: 222 official ha against 153 ha of perimeter; similar, but with reservations.
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.