Fresnillo fire, April 2021 Fresnillo, Sombrerete
The fire started on 20 April 2021 in Fresnillo, Mexico, and satellites saw it burning for 3 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 1,989 hectares from heat detections, spread across 2 municipalities.
It is the 27th largest in Zacatecas since 2016 (of 31 with a page). Number 203 in Mexico in 2021, of 295.
- Burnt area
- 1,989ha
- GWIS perimeter (Copernicus)
- Duration
- 3days
- 20 Apr 2021 – 22 Apr 2021
- Municipalities hit
- 2
- municipalities
- Started on
- 20 Apr
- 2021
- Heat detections
- 92
- in a single hotspot: 259 MW
- Danger at start
- 46
- Very high · FWI index
- Energy released
- 2.6GW
- sum of detected power
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 15 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
-
1,598 ha reached on 20 Apr0.3 %
-
400 ha reached on 20 Apr0.1 %
Burnt area inside each municipality, from crossing the GWIS 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.
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) |
|---|---|---|---|---|---|
| 20 Apr | 23.0 °C | 12 % | 49 km/h | 0.0 mm | Very high 46 |
| 21 Apr | 23.4 °C | 10 % | 52 km/h | 0.0 mm | Very high 49 |
| 22 Apr | 23.1 °C | 15 % | 58 km/h | 0.0 mm | Extreme 51 |
| 23 Apr after | 22.2 °C | 16 % | 66 km/h | 0.0 mm | Extreme 55 |
| 24 Apr after | 24.6 °C | 7 % | 29 km/h | 0.0 mm | High 38 |
| 25 Apr after | 25.9 °C | 14 % | 44 km/h | 0.0 mm | Very high 47 |
| 26 Apr after | 24.4 °C | 22 % | 48 km/h | 0.0 mm | Very high 44 |
| 27 Apr after | 23.6 °C | 20 % | 60 km/h | 0.0 mm | Extreme 51 |
| 28 Apr after | 23.0 °C | 29 % | 71 km/h | 0.0 mm | Extreme 50 |
| 29 Apr after | 23.6 °C | 25 % | 62 km/h | 0.0 mm | Very high 45 |
| 30 Apr after | 21.9 °C | 23 % | 66 km/h | 0.8 mm | Very high 40 |
| 1 May after | 21.2 °C | 16 % | 56 km/h | 0.0 mm | Very high 44 |
| 2 May after | 24.4 °C | 6 % | 41 km/h | 0.0 mm | Very high 47 |
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.
Detections table · 92Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Frequently asked questions
- How long did the Fresnillo fire last?
- GWIS (Copernicus) dates it between 20 April 2021 and 22 April 2021: 3 days between the first and last heat detection of the perimeter.
- How much area did it burn?
- The perimeter GWIS (Copernicus) rebuilt from heat detections is 1,989 hectares (19.9 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire entered 2 municipalities: Fresnillo (1,598 ha, 0.3 %); Sombrerete (400 ha, 0.1 %).
- What was the weather like?
- During the fire the temperature reached 23.4 °C, humidity dropped to 10 % and gusts hit 58 km/h. The fire danger index (FWI) reached 51, class Extreme.
- Where does this data come from?
- From the GWIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Mexico (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: 911
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
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 ADM2 (Creative Commons Attribution 4.0 (CC BY 4.0)). 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.