Tendais fire, September 2024
Tendais, Cinfães, São Cristóvão de Nogueira
Out · last detection 18 Sept 2024, 14:00 UTC
The fire started on 16 September 2024 in Tendais, Portugal, and satellites saw it burning for 3 days. Copernicus mapped a burnt perimeter of 953 hectares from satellite imagery, spread across 3 freguesias.
It is the 3th largest in Cinfães since 2016 (of 31 with a page). Number 23 in Portugal in 2024, of 69.
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
953ha
Perimeter published by EFFIS (Copernicus).
This page953ICNF1,202
Source
EFFIS (Copernicus)
Date
perimeter revised on 1 October 2024
+− cross-check
ICNF: 1,202 ha (matched records: 4). Difference between the page and the official record: −20.7%. 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
3days
16 Sept 2024 to 18 Sept 2024: first and last day with fire on the page.
Source
EFFIS (Copernicus) · NASA FIRMS · VIIRS
Date
last detection: 18 Sept 2024, 14:00 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
16 Sept 2024
First day with fire seen by the satellites or the perimeter.
Source
EFFIS (Copernicus) · NASA FIRMS · VIIRS
Date
16 Sept 2024
+− 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
83
VIIRS detections at 375 m. Most intense hotspot: 49 MW.
Source
NASA FIRMS · VIIRS (Suomi NPP)
Date
16 Sept 2024 – 18 Sept 2024
+− 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
471MW
Total radiative power on 16 September 2024; hotspots that day: 27.
Source
NASA FIRMS · VIIRS (FRP)
Date
16 Sept 2024
+− 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
57.7FWI · extreme
Fire Weather Index (Canadian system) computed by WorldFires for the day the fire started. Consecutive days without rain before: 8.
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
27.4°C · 14% RH
High of 27.4 °C and minimum humidity of 14% on 16 September 2024; gusts of 56 km/h on 17 September 2024.
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: 1,202 ha (records: 4).
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
Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.
The weather it burned in
27°high
56km/h · peak gust
14%lowest humidity
It had gone 8 days without rain (1 mm or more) when it started. Rain came after the fire: 7.4 mm on 20 Sept.
This area had burned before
92% of the perimeter overlaps earlier fires recorded since 2016: 687 ha in 2016, 122 ha in 2017, 1 ha in 2019, 376 ha in 2020, 92 ha in 2021, 93 ha in 2022, 129 ha in 2023. Part of it burned more than once, so the yearly figures add up to more than the 876 ha that had burned before.
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.
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 2025
Built-up area0.63ha
Residents< 20
Inside the perimeter there were about 0.63 hectares of built-up land and almost nobody lived there (GHSL 2025, 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. The GHSL 2025 epoch is a projection made from 2020 and earlier data.
According to ICNF, 4 fires started inside this perimeter on these dates, totalling 1,202 ha (the satellite measured 953 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.
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)
It was 2.0 times larger than the median of its twins and lasted 3 days, against 3 days.
Only 7 of its 17 twins burned more. The weather on the first day does not explain everything: the wind in the following days, the fuel and the firefighting also count. In 7 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 3.2 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
7.4 mmfirst rain
20 Sept2 days after it ended
56km/h · max. gust
It was considered over on 18 Sept, and on 20 Sept 7.4 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 10 of 17, with a median of 3.2 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 Sept 2024
After · 25 Sept 2024
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 19 September 2024 the air beside the fire reached 371 µg/m³ of PM2.5. That day averaged 174: 12 times the WHO daily guideline (15).
PM2.5 peak371µg/m³
Days over the guideline4days
PM10452µg/m³
Optical depth4.89
WHO 15
14 Sept16 Sept18 Sept20 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· 83Every 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 16 September 2024 and 18 September 2024: 3 days between the first and last image with fire.
How much area did it burn?
The perimeter Copernicus measured from satellite imagery is 953 hectares (9.5 km²). Official national figures may differ.
Which freguesias burned?
The fire entered 3 freguesias: Tendais (597 ha, 19 %); Cinfães (356 ha, 14 %); São Cristóvão de Nogueira (0 ha, 0.0 %).
Did the fire reach a town?
The fire started in Tendais and came within 1.0 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 27.4 °C, humidity dropped to 14 % and gusts hit 56 km/h. The fire danger index (FWI) reached 58, class Extreme.
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 3 days and their median area 487 ha; 41 % went past 1,000 ha. Only 7 of its 17 twins burned more. The weather on the first day does not explain everything: the wind in the following days, the fuel and the firefighting also count. In 7 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 3.2 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. 83 Suomi-NPP VIIRS detections on those dates.
Compared with ICNF: 1,202 official ha against 953 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 2025, 100 m cells), summed inside the perimeter: an estimate of what was there, not a damage count.
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.