San Pedro fire, December 2025 San Pedro, San Antonio
The fire started on 16 December 2025 in San Pedro, Chile, and satellites saw it burning for 3 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 3,754 hectares from heat detections, spread across 2 municipalities.
It is the 6th largest in Región Metropolitana de Santiago since 2016 (of 29 with a page). Number 3 in Chile in 2025, of 39.
Compare with…
- Burnt area
- 3,754ha
- GWIS perimeter (Copernicus)
- Duration
- 3days
- 16 Dec 2025 – 18 Dec 2025
- Municipalities hit
- 2
- communes
- Started on
- 16 Dec
- 2025
- Heat detections
- 97
- in a single hotspot: 101 MW
- Danger at start
- 26
- High · FWI index
- Average daily power
- 504MW
- detected power per day, on average
Where it burned
How it evolved, day by day
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 9 days without rain (1 mm or more) when it started.
This area had burned before
8% of the perimeter overlaps earlier fires recorded since 2016: 318 ha in 2016.
How big is it?
London boundary: geoBoundaries · Office for National Statistics (Open Government Licence v3.0).
Paris boundary: geoBoundaries · Institut national de l'information géographique et forestière (IGN-F) (Etalab Open License 2.0).
Madrid boundary: geoBoundaries · Open Data ESRI, IGN Central Registry of Cartography Area (CC BY 4.0).
Berlin boundary: geoBoundaries · Federal Agency for Cartography and Geodesy (dl-de/by-2-0).
This compares size, not location: both shapes are at the same scale, north up, centred on each other.
What happened to each town
-
San Pedro where it started3,654 ha reached on 16 Dec4.6 %
-
106 ha0.3 %
Burnt area inside each municipality, from crossing the GWIS 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.
People and buildings inside the perimeter
GHSL 2025Inside the perimeter there were about 7.9 hectares of built-up land and about 100 residents (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.
Source: Global Human Settlement Layer (GHS-BUILT-S and GHS-POP R2023A), European Commission Joint Research Centre (JRC), © European Union, CC BY 4.0. Sum inside the perimeter computed by WorldFires. human-settlement.emergency.copernicus.eu
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) |
|---|---|---|---|---|---|
| 16 Dec | 29.7 °C | 31 % | 42 km/h | 0.0 mm | High 26 |
| 17 Dec | 22.5 °C | 56 % | 37 km/h | 0.0 mm | Moderate 16 |
| 18 Dec | 23.2 °C | 55 % | 38 km/h | 0.0 mm | Moderate 16 |
| 19 Dec after | 21.4 °C | 59 % | 37 km/h | 0.0 mm | Moderate 16 |
| 20 Dec after | 20.3 °C | 59 % | 38 km/h | 0.0 mm | Moderate 15 |
| 21 Dec after | 23.9 °C | 47 % | 42 km/h | 0.0 mm | Moderate 18 |
| 22 Dec after | 25.1 °C | 41 % | 47 km/h | 0.0 mm | High 22 |
| 23 Dec after | 27.8 °C | 36 % | 48 km/h | 0.0 mm | High 26 |
| 24 Dec after | 28.9 °C | 29 % | 51 km/h | 0.0 mm | High 31 |
| 25 Dec after | 31.0 °C | 27 % | 45 km/h | 0.0 mm | High 32 |
| 26 Dec after | 22.8 °C | 53 % | 37 km/h | 0.0 mm | Moderate 20 |
| 27 Dec after | 28.3 °C | 39 % | 46 km/h | 0.0 mm | High 25 |
| 28 Dec after | 26.2 °C | 45 % | 36 km/h | 0.0 mm | High 22 |
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 18 December 2025 the air beside the fire reached 151 µg/m³ of PM2.5. That day averaged 88: 5.8 times the WHO daily 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 · 97Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
- 3,925 haSanto Domingo15 December 2022 · 7 days · 10 km away
- 4,693 haSanto DomingoJanuary 2017 · 4 days · 19 km away
- 3,595 haSanto DomingoJanuary 2019 · 2 days · 23 km away
- 4,064 haSan AntonioDecember 2016 · 6 days · 27 km away
- 9,675 haSan PedroJanuary 2017 · 9 days · 28 km away
- 3,932 haLituecheNovember 2016 · 2 days · 32 km away
Frequently asked questions
- How long did the San Pedro fire last?
- According to the heat detections seen by satellite inside the perimeter, it burned from 16 December 2025 to 18 December 2025 (3 days). The perimeter dates it from 16 December 2025 to 17 December 2025.
- How much area did it burn?
- The perimeter GWIS (Copernicus) rebuilt from heat detections is 3,754 hectares (37.5 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire entered 2 municipalities: San Pedro (3,654 ha, 4.6 %); San Antonio (106 ha, 0.3 %).
- What was the weather like?
- During the fire the temperature reached 29.7 °C, humidity dropped to 31 % and gusts hit 42 km/h. The fire danger index (FWI) reached 26, class High.
- Where does this data come from?
- From the GWIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Chile (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: 130 (CONAF) · 132 · Emergency number and official warnings ›
Satellite cross-check
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.
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: GWIS (Copernicus), rebuilt from heat detections rather than mapped on imagery.
- Dates adjusted with the VIIRS detections inside the perimeter, which said 16 December 2025 to 17 December 2025. 97 Suomi-NPP VIIRS detections on those dates.
- We have not matched this page with any official record.
- 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.
Where this data comes from
The perimeter comes from the Copernicus Global Wildfire Information System (GWIS), which rebuilds it from MODIS and VIIRS heat detections and publishes it under CC BY 4.0. It is not measured on imagery as in Europe, so it is an estimate. 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 (Creative Commons Attribution 3.0 Intergovernmental Organisations (CC BY 3.0 IGO)). The area per municipality is computed by WorldFires by crossing the perimeter with those boundaries, so it may differ from each country’s official figure.