Loulé fire, August 2021 Loulé (São Clemente), São Brás de Alportel
The fire started on 4 August 2021 in Loulé (São Clemente), Portugal, and satellites saw it burning for 4 days. Copernicus mapped a burnt perimeter of 191 hectares from satellite imagery, spread across 2 municipalities.
Number 15 in Portugal in 2021, of 30.
The power measured by the satellite is low (6.0 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…
- Burnt area
- 191ha
- Copernicus perimeter
- Duration
- 4days
- 4 Aug 2021 – 7 Aug 2021
- Municipalities hit
- 2
- freguesias
- Started on
- 4 Aug
- 2021
- Heat detections
- 1
- in a single hotspot: 6 MW
- Danger at start
- 40
- Very high · FWI index
- Average daily power
- 6MW
- detected power per day, on average
Where it burned
How it evolved, day by day
6 Aug 2021 · 6 MW · 1
Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.
The weather it burned in
It had gone 44 days without rain (1 mm or more) when it started.
This area had burned before
No earlier perimeters overlap this fire since 2016, when the satellite record begins.
What happened to each town
-
188 ha reached on 6 Aug4.1 %
-
São Brás de Alportel 11,248 inhabitants · 7.2 km from the town4 ha0.0 %
Burnt area inside each municipality, from crossing the official perimeter with administrative boundaries. The distance is from the town centre to the nearest fire: staying a kilometre away does not mean it reached the houses.
What burned
- Sclerophyllous scrub91 %
- Agricultural areas8.9 %
Natura 2000 protected area affected: 100 %
- LIC Barrocal PTCON0049
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
According to ICNF, 2 fires started inside this perimeter on these dates, totalling 241 ha (the satellite measured 191 ha). The two figures differ a lot, so these may not be exactly the same fire: take them as nearby records.
- Loulé Querença 4 August 2021 · 13:46 226 ha · extinguished on 5 August 2021 · cause: arson
- Loulé São Clemente 4 August 2021 · 13:49 16 ha · extinguished on 5 August 2021 · cause: arson
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 Aug | 32.0 °C | 36 % | 46 km/h | 0.0 mm | Very high 40 |
| 5 Aug | 33.9 °C | 22 % | 44 km/h | 0.0 mm | Very high 49 |
| 6 Aug | 32.5 °C | 24 % | 46 km/h | 0.0 mm | Extreme 50 |
| 7 Aug | 27.6 °C | 33 % | 46 km/h | 0.0 mm | Very high 46 |
| 8 Aug after | 29.2 °C | 25 % | 43 km/h | 0.0 mm | Very high 44 |
| 9 Aug after | 29.9 °C | 25 % | 37 km/h | 0.0 mm | Very high 39 |
| 10 Aug after | 33.6 °C | 27 % | 33 km/h | 0.0 mm | Very high 41 |
| 11 Aug after | 31.3 °C | 35 % | 34 km/h | 0.0 mm | Very high 40 |
| 12 Aug after | 34.9 °C | 27 % | 24 km/h | 0.0 mm | Very high 38 |
| 13 Aug after | 36.6 °C | 26 % | 25 km/h | 0.0 mm | Very high 40 |
| 14 Aug after | 39.6 °C | 18 % | 24 km/h | 0.0 mm | Very high 43 |
| 15 Aug after | 40.1 °C | 13 % | 39 km/h | 0.0 mm | Extreme 64 |
| 16 Aug after | 37.0 °C | 13 % | 49 km/h | 0.0 mm | Extreme 69 |
| 17 Aug after | 36.2 °C | 19 % | 46 km/h | 0.0 mm | Extreme 64 |
Before and after, from space
Drag the line to compare the same ground before the fire and after it.
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 · CopernicusOn 10 August 2021 the air beside the fire reached 7 µg/m³ of PM2.5, but no daily average passed the WHO guideline (15).
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 · 1Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
- 647 haFaro AlmancilJuly 2022 · 4 days · 14 km away
- 988 haLoulé AmeixialJune 2026 · 1 day · 22 km away
- 1,068 haAlmodôvar Santa CruzSeptember 2018 · 1 day · 26 km away
- 7,414 haCastro Marim OdeleiteAugust 2021 · 2 days · 36 km away
- 1,879 haSilves São Marcos da SerraAugust 2016 · 1 day · 37 km away
- 1,322 haSilves São Marcos da SerraJuly 2022 · 2 days · 38 km away
Frequently asked questions
- How long did the Loulé fire last?
- Copernicus dates it between 4 August 2021 and 7 August 2021: 4 days between the first and last image with fire.
- How much area did it burn?
- The perimeter Copernicus measured from satellite imagery is 191 hectares (1.9 km²). Official national figures may differ.
- Which municipalities burned?
- The fire entered 2 municipalities: Loulé (São Clemente) (188 ha, 4.1 %); São Brás de Alportel (4 ha, 0.0 %).
- Did the fire reach a town?
- The closest fire to a town centre came within 5.0 km of Loulé (São Clemente). That is the distance to the perimeter or nearest hotspot; it does not mean it entered the houses.
- What was the weather like?
- During the fire the temperature reached 33.9 °C, humidity dropped to 22 % and gusts hit 46 km/h. The fire danger index (FWI) reached 50, 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.
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
- ICNF · Instituto da Conservação da Natureza e das Florestas ↗
- ANEPC · Proteção Civil ↗
- Fogos.pt (ocorrências em tempo real) ↗
Satellite cross-check
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
How we know this
- Perimeter: EFFIS (Copernicus), mapped on satellite imagery.
- Dates from the perimeter: the VIIRS detections inside it did not change them. One Suomi-NPP VIIRS detection on those dates.
- Compared with ICNF: 241 official ha against 191 ha of perimeter; similar, but with reservations.
- Weather: Copernicus ERA5 reanalysis at the fire location, in cells of about 25 km.
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.