Seixo de Ansiães fire, August 2016
Seixo de Ansiães, Lavandeira, Beira Grande e Selores
Out · last detection 29 Aug 2016, 13:22 UTC
The fire started on 28 August 2016 in Seixo de Ansiães, Portugal, and satellites saw it burning for 2 days. Copernicus mapped a burnt perimeter of 127 hectares from satellite imagery, spread across 2 freguesias.
It is the 10th largest in Carrazeda de Ansiães since 2016 (of 10 with a page). Number 155 in Portugal in 2016, of 180.
The power measured by the satellite is low (6.6 MW in the strongest hotspot), more typical of grass or stubble burning, or a slow surface fire, than of a large crown fire.
matches the official recordwith caveatssatellite onlymodel
When copying, the sentence is
Tick the figures you want: they make up the lede and the CSV.
Burned area
with caveats
127ha
Perimeter published by EFFIS (Copernicus).
This page127ICNF262
Source
EFFIS (Copernicus)
Date
perimeter revised on 26 January 2022
+− cross-check
ICNF: 262 ha (matched records: 1). Difference between the page and the official record: −51.5%. Matched on 8 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
2days
28 Aug 2016 to 29 Aug 2016: first and last day with fire on the page.
Source
EFFIS (Copernicus) · NASA FIRMS · VIIRS
Date
last detection: 29 Aug 2016, 13:22 UTC
+− 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
28 Aug 2016
First day with fire seen by the satellites or the perimeter.
Source
EFFIS (Copernicus) · NASA FIRMS · VIIRS
Date
28 Aug 2016
+− cross-check
The two figures differ a lot, so these may not be exactly the same fire: take them as nearby records.
Hotspots
satellite only
2
VIIRS detections at 375 m. Most intense hotspot: 7 MW.
Source
NASA FIRMS · VIIRS (Suomi NPP)
Date
28 Aug 2016 – 29 Aug 2016
+− cross-check
There is no official record to compare with. Each hotspot is a pixel detected in one satellite pass, not a separate fire.
The worst day
satellite only
7MW
Total radiative power on 28 August 2016; hotspots that day: 1.
Source
NASA FIRMS · VIIRS (FRP)
Date
28 Aug 2016
+− cross-check
Fire radiative power (FRP) measures the energy the fire gives off when the satellite passes. Added up by day, it compares intensity, not area.
Danger at the start
model
26.6FWI · high
Fire Weather Index (Canadian system) computed by WorldFires for the day the fire started. Consecutive days without rain before: 1.
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
28.7°C · 31% RH
High of 28.7 °C and minimum humidity of 31% on 28 August 2016; gusts of 33 km/h on 28 August 2016.
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
· reconstructedofficial
Matched with the official ICNF record
Nearby records with very different figures: 262 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
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
Scrub and transitional woodland64 %
Agricultural areas30 %
Other natural land6.4 %
Land cover inside the perimeter according to Corine Land Cover, as reported by Copernicus.
Official record
According to ICNF, this fire started on 28 August 2016 and burned 262 ha (the satellite measured 127 ha). The two figures differ a lot, so these may not be exactly the same fire: take them as nearby records.
Carrazeda de AnsiãesSeixo de Ansiães28 August 2016 · 15:55262 ha· extinguished on 28 August 2016· cause: rekindling
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)
28 Aug
28.7 °C
31 %
33 km/h
0.0 mm
High 27
29 Aug
27.0 °C
36 %
26 km/h
0.0 mm
High 27
30 Aug after
26.7 °C
28 %
31 km/h
0.0 mm
High 25
31 Aug after
28.3 °C
31 %
23 km/h
0.0 mm
High 25
1 Sept after
29.8 °C
30 %
22 km/h
0.0 mm
High 25
2 Sept after
31.4 °C
28 %
22 km/h
0.0 mm
High 25
3 Sept after
31.8 °C
24 %
28 km/h
0.0 mm
High 27
4 Sept after
31.2 °C
28 %
30 km/h
0.0 mm
High 32
5 Sept after
32.2 °C
26 %
16 km/h
0.0 mm
High 28
6 Sept after
34.9 °C
18 %
40 km/h
0.0 mm
High 38
7 Sept after
32.0 °C
26 %
41 km/h
0.0 mm
High 36
8 Sept after
25.4 °C
36 %
27 km/h
0.0 mm
High 27
Its twins: fires that started in the same weather
It started with an FWI of 26.6, a minimum humidity of 31% and 1 day without rain. Fires in the area that started in weather like this since 2016: 32.
FWI at the start26.6
Minimum humidity31 %
Days without rain1
this firechosen twinsrest of the area
Almost identicalSimilar
Outlines of the closest twins
This fire · Seixo de Ansiães fire, August 2016
127 ha2 daysFWI 26.6Min. humidity 31 %
São João da Pesqueira fire, July 2020
780 ha2 daysFWI 26.6Min. humidity 31 %31 km away, in 2020
First rain (1 mm or more) after it ended: 1.7 mm on 21 Jul.
It stayed below its twins: 127 ha against a median of 206 ha. It lasted 2 days, against 2 days.
In 12 of 32, 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 2.3 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
—first rain
—no rain in ten days
33km/h · max. gust
It was considered over on 29 Aug, and not even 1 mm fell in the following ten days: it went out without rain. Twins with rain when they ended: 20 of 32, with a median of 2.3 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 · 21 Aug 2016
After · 5 Sept 2016
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 26 August 2016 the air beside the fire reached 21 µg/m³ of PM2.5. That day averaged 16: 1.1 times the WHO daily guideline (15).
PM2.5 peak21µg/m³
Days over the guideline2days
PM1039µg/m³
WHO 15
26 Aug28 Aug30 Aug1 Sept
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· 2Every 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.
Copernicus dates it between 28 August 2016 and 29 August 2016: 2 days between the first and last image with fire.
How much area did it burn?
The perimeter Copernicus measured from satellite imagery is 127 hectares (1.3 km²). Official national figures may differ.
Which freguesias burned?
The fire entered 2 freguesias: Seixo de Ansiães (124 ha, 5.2 %); Lavandeira, Beira Grande e Selores (3 ha, 0.1 %).
Did the fire reach a town?
The fire started in Seixo de Ansiães and came within 1.1 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 28.7 °C, humidity dropped to 31 % and gusts hit 33 km/h. The fire danger index (FWI) reached 27, 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.
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: 32. Their median duration was 2 days and their median area 206 ha; 9 % went past 1,000 ha. In 12 of 32, 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 2.3 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. 2 Suomi-NPP VIIRS detections on those dates.
Compared with ICNF: 262 official ha against 127 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.