San Dimas fire, April 2018 San Dimas
The fire started on 28 April 2018 in San Dimas, Mexico, and satellites saw it burning for 8 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 1,952 hectares from heat detections, spread across a single municipality.
It is the 167th largest in Durango since 2016 (of 239 with a page). Number 155 in Mexico in 2018, of 233.
The power measured by the satellite is low (15.0 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
- 1,952ha
- GWIS perimeter (Copernicus)
- Duration
- 8days
- 28 Apr 2018 – 5 May 2018
- Municipalities hit
- 1
- municipalities
- Started on
- 28 Apr
- 2018
- Heat detections
- 79
- in a single hotspot: 15 MW
- Danger at start
- 34
- High · FWI index
- Average daily power
- 47MW
- 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 17 days without rain (1 mm or more) when it started. Rain came after the fire: 12.1 mm on 6 May.
This area had burned before
No earlier perimeters overlap this fire since 2016, when the satellite record begins.
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 Dimas where it started1,960 ha0.4 %
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 2020Inside the perimeter there was no noticeable built-up land and almost nobody lived there (GHSL 2020, 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.
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
Several official records match this area
According to CONAFOR, 2 fires started inside this perimeter on these dates, totalling 1,269 ha (the satellite measured 1,952 ha). The two figures differ a lot, so these may not be exactly the same fire: take them as nearby records.
CONAFOR 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.
- 1 San Dimas Ejido San Bartolo 24 April 2018 40 ha · extinguished on 30 April 2018 · cause: negligence
- 2 San Dimas Ejido San Bartolo y Ejido Guarisamey y Anexos 29 April 2018 1,229 ha · extinguished on 4 May 2018 · cause: negligence
Total according to CONAFOR: 1,269 ha, 65 % of the 1,952 ha in the satellite perimeter.
CONAFOR (Comisión Nacional Forestal), estadística de incendios forestales en datos.gob.mx (CC BY 4.0). This is the agency’s consolidated statistic: it measures the area in its own way, which is why it can differ from the satellite.
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) |
|---|---|---|---|---|---|
| 28 Apr | 22.4 °C | 29 % | 58 km/h | 0.4 mm | High 34 |
| 29 Apr | 22.6 °C | 27 % | 60 km/h | 0.0 mm | High 35 |
| 30 Apr | 22.8 °C | 26 % | 68 km/h | 0.2 mm | Very high 38 |
| 1 May | 24.4 °C | 21 % | 64 km/h | 0.0 mm | High 37 |
| 2 May | 23.1 °C | 28 % | 58 km/h | 0.0 mm | High 35 |
| 3 May | 23.5 °C | 32 % | 54 km/h | 0.0 mm | High 33 |
| 4 May | 25.3 °C | 30 % | 45 km/h | 0.2 mm | High 31 |
| 5 May | 25.8 °C | 35 % | 39 km/h | 1.8 mm | Moderate 12 |
| 6 May after | 25.1 °C | 37 % | 39 km/h | 12.1 mm | Very low 3 |
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 · 79Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
Frequently asked questions
- How long did the San Dimas fire last?
- GWIS (Copernicus) dates it between 28 April 2018 and 5 May 2018: 8 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 1,952 hectares (19.5 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire only entered San Dimas (1,960 ha, 0.4 %).
- What was the weather like?
- During the fire the temperature reached 25.8 °C, humidity dropped to 21 % and gusts hit 68 km/h. The fire danger index (FWI) reached 38, class Very high.
- 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 · 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 from the perimeter: the VIIRS detections inside it did not change them. 79 Suomi-NPP VIIRS detections on those dates.
- Compared with CONAFOR: 1,269 official ha against 1,952 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 2020, 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 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.