San Ignacio fire, 1 May 2023 San Ignacio
The fire started on 1 May 2023 in San Ignacio, Mexico, and satellites saw it burning for 13 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 4,333 hectares from heat detections, spread across a single municipality.
It is the 25th largest in Sinaloa since 2016 (of 82 with a page). Number 59 in Mexico in 2023, of 285.
The power measured by the satellite is low (27.6 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
- 4,333ha
- GWIS perimeter (Copernicus)
- Duration
- 13days
- 1 May 2023 – 13 May 2023
- Municipalities hit
- 1
- municipalities
- Started on
- 1 May
- 2023
- Heat detections
- 207
- in a single hotspot: 28 MW
- Danger at start
- 39
- Very high · FWI index
- Average daily power
- 79MW
- 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 more than two months without rain (1 mm or more) when it started. Rain came after the fire: 1.6 mm on 16 May.
This area had burned before
63% of the perimeter overlaps earlier fires recorded since 2016: 970 ha in 2016, 2,652 ha in 2019. Part of it burned more than once, so the yearly figures add up to more than the 2,710 ha that had burned before.
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 Ignacio where it started4,360 ha reached on 1 May0.9 %
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 0.11 hectares of built-up land and about 20 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
Official record
According to CONAFOR, this fire started on 5 May 2023 and burned 3,169 ha (the satellite measured 4,333 ha). The two figures differ a lot, so these may not be exactly the same fire: take them as nearby records.
- San Ignacio Los Potreros 5 May 2023 3,169 ha · extinguished on 14 May 2023 · cause: unknown
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) |
|---|---|---|---|---|---|
| 1 May | 28.4 °C | 27 % | 45 km/h | 0.0 mm | Very high 39 |
| 2 May | 29.8 °C | 21 % | 41 km/h | 0.0 mm | High 38 |
| 3 May | 31.9 °C | 21 % | 47 km/h | 0.0 mm | Very high 40 |
| 4 May | 32.0 °C | 22 % | 40 km/h | 0.0 mm | High 38 |
| 5 May | 33.5 °C | 18 % | 42 km/h | 0.0 mm | Very high 42 |
| 6 May | 35.4 °C | 13 % | 55 km/h | 0.0 mm | Extreme 52 |
| 7 May | 35.0 °C | 10 % | 46 km/h | 0.0 mm | Extreme 51 |
| 8 May | 35.0 °C | 9 % | 46 km/h | 0.0 mm | Extreme 52 |
| 9 May | 33.7 °C | 11 % | 46 km/h | 0.0 mm | Extreme 52 |
| 10 May | 33.2 °C | 13 % | 45 km/h | 0.0 mm | Extreme 52 |
| 11 May | 32.5 °C | 12 % | 45 km/h | 0.0 mm | Extreme 53 |
| 12 May | 31.7 °C | 9 % | 42 km/h | 0.0 mm | Extreme 52 |
| 13 May | 31.3 °C | 14 % | 47 km/h | 0.0 mm | Extreme 52 |
| 14 May after | 30.5 °C | 24 % | 45 km/h | 0.0 mm | Very high 44 |
| 15 May after | 32.0 °C | 20 % | 45 km/h | 0.2 mm | Very high 44 |
| 16 May after | 31.1 °C | 24 % | 40 km/h | 1.6 mm | High 26 |
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 9 May 2023 the air beside the fire reached 47 µg/m³ of PM2.5. That day averaged 29: 1.9 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 · 207Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
- 15,732 haTamazula19 May 2018 · 24 days · 20 km away
- 9,253 haSan IgnacioApril 2025 · 18 days · 30 km away
- 12,257 haTamazula30 May 2019 · 31 days · 36 km away
- 6,006 haTamazula23 May 2017 · 19 days · 36 km away
- 49,719 haSan IgnacioMarch 2025 · 65 days · 38 km away
- 6,040 haTamazula22 May 2023 · 13 days · 40 km away
Frequently asked questions
- How long did the San Ignacio fire last?
- According to the heat detections seen by satellite inside the perimeter, it burned from 1 May 2023 to 13 May 2023 (13 days). The perimeter dates it from 3 May 2023 to 13 May 2023.
- How much area did it burn?
- The perimeter GWIS (Copernicus) rebuilt from heat detections is 4,333 hectares (43.3 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire only entered San Ignacio (4,360 ha, 0.9 %).
- What was the weather like?
- During the fire the temperature reached 35.4 °C, humidity dropped to 9 % and gusts hit 55 km/h. The fire danger index (FWI) reached 53, 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 · 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.
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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 3 May 2023 to 13 May 2023. 207 Suomi-NPP VIIRS detections on those dates.
- Compared with CONAFOR: 3,169 official ha against 4,333 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.
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.