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MX · Mexico · –

San Luis Acatlán fire, April 2019 San Luis Acatlán, Ayutla de los Libres, Cuautepec

Out · last detection 27 May 2019, 20:32 UTC

The fire started on 21 April 2019 in San Luis Acatlán, Mexico, and satellites saw it burning for 37 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 18,688 hectares from heat detections, spread across 4 municipalities.

It is the 13th largest in Guerrero since 2016 (of 582 with a page). Number 9 in Mexico in 2019, of 363.

Burnt area
18,688ha
GWIS perimeter (Copernicus)
Duration
37days
21 Apr 2019 – 27 May 2019
Municipalities hit
4
municipalities
Started on
21 Apr
2019
Heat detections
1,208
in a single hotspot: 72 MW
Danger at start
25
High · FWI index
Average daily power
202MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 21 Apr27 May
27 May 2019

How it evolved, day by day

21 Apr 2019 · 9 MW · 5 23 Apr 2019 · 1 MW · 2 25 Apr 2019 · 40 MW · 10 26 Apr 2019 · 9 MW · 4 27 Apr 2019 · 10 MW · 1 28 Apr 2019 · 119 MW · 18 29 Apr 2019 · 32 MW · 21 30 Apr 2019 · 27 MW · 4 1 May 2019 · 28 MW · 5 2 May 2019 · 233 MW · 27 3 May 2019 · 160 MW · 34 4 May 2019 · 314 MW · 47 5 May 2019 · 312 MW · 60 6 May 2019 · 684 MW · 115 7 May 2019 · 1,343 MW · 133 8 May 2019 · 880 MW · 109 9 May 2019 · 489 MW · 99 10 May 2019 · 163 MW · 52 11 May 2019 · 70 MW · 17 12 May 2019 · 43 MW · 11 13 May 2019 · 228 MW · 38 14 May 2019 · 256 MW · 50 15 May 2019 · 325 MW · 63 16 May 2019 · 129 MW · 42 17 May 2019 · 103 MW · 8 18 May 2019 · 225 MW · 44 20 May 2019 · 106 MW · 20 21 May 2019 · 176 MW · 28 22 May 2019 · 35 MW · 23 23 May 2019 · 145 MW · 37 24 May 2019 · 38 MW · 23 25 May 2019 · 20 MW · 16 26 May 2019 · 95 MW · 27 27 May 2019 · 39 MW · 15
21 Apr 30 Apr 7 May 14 May 22 May

Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.

The weather it burned in

32°high
49km/h · peak gust
28%lowest humidity

It had gone 0 days without rain (1 mm or more) when it started. Rain came after the fire: 10.4 mm on 28 May.

This area had burned before

6% of the perimeter overlaps earlier fires recorded since 2016: 1,187 ha in 2018.

How big is it?

10 km
It burned the equivalent of 12% of the area of London (187 km² against 1,583 km²).

London boundary: geoBoundaries · Office for National Statistics (Open Government Licence v3.0).

This compares size, not location: both shapes are at the same scale, north up, centred on each other.

What happened to each town

  1. San Luis Acatlán where it started
    14,841 ha reached on 21 Apr
    13 %
  2. 2,812 ha reached on 14 May
    2.7 %
  3. 1,773 ha reached on 30 Apr
    5.6 %
  4. 33 ha
    0.1 %

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 2020
Built-up area0.39 ha
Residents≈ 40

Inside the perimeter there were about 0.39 hectares of built-up land and about 40 residents (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

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)
21 Apr 29.3 °C 43 % 44 km/h 0.0 mm High 25
22 Apr 28.8 °C 41 % 42 km/h 0.0 mm High 30
23 Apr 30.8 °C 39 % 38 km/h 0.0 mm High 32
24 Apr 28.6 °C 38 % 38 km/h 0.0 mm High 32
25 Apr 29.4 °C 33 % 37 km/h 0.0 mm High 35
26 Apr 29.5 °C 34 % 39 km/h 0.0 mm High 36
27 Apr 31.7 °C 30 % 49 km/h 0.0 mm Very high 40
28 Apr 31.1 °C 39 % 42 km/h 0.0 mm Very high 38
29 Apr 31.1 °C 37 % 41 km/h 0.0 mm Very high 40
30 Apr 30.2 °C 43 % 36 km/h 0.8 mm High 35
1 May 31.0 °C 37 % 42 km/h 0.0 mm High 31
2 May 30.4 °C 40 % 46 km/h 0.0 mm High 35
3 May 30.6 °C 35 % 46 km/h 0.0 mm High 36
4 May 29.6 °C 41 % 41 km/h 0.0 mm High 35
5 May 28.5 °C 43 % 36 km/h 0.0 mm High 34
6 May 29.7 °C 42 % 36 km/h 0.0 mm High 35
7 May 31.1 °C 34 % 38 km/h 0.0 mm High 37
8 May 30.6 °C 28 % 36 km/h 0.0 mm Very high 40
9 May 29.1 °C 31 % 38 km/h 0.0 mm Very high 41
10 May 28.9 °C 40 % 37 km/h 0.0 mm High 37
11 May 28.0 °C 48 % 37 km/h 0.0 mm High 32
12 May 28.6 °C 47 % 34 km/h 0.0 mm High 32
13 May 28.7 °C 38 % 37 km/h 0.0 mm High 33
14 May 29.5 °C 35 % 35 km/h 0.0 mm High 36
15 May 30.4 °C 31 % 38 km/h 0.0 mm Very high 39
16 May 29.3 °C 45 % 40 km/h 0.9 mm High 36
17 May 29.2 °C 49 % 35 km/h 2.3 mm High 26
18 May 30.3 °C 54 % 37 km/h 3.3 mm Low 10
19 May 29.1 °C 54 % 36 km/h 0.6 mm Low 10
20 May 29.8 °C 55 % 35 km/h 1.7 mm Moderate 18
21 May 30.7 °C 46 % 37 km/h 0.0 mm Moderate 18
22 May 29.3 °C 46 % 35 km/h 0.0 mm High 23
23 May 29.7 °C 45 % 31 km/h 0.0 mm High 26
24 May 30.7 °C 52 % 34 km/h 0.6 mm High 25
25 May 28.5 °C 62 % 31 km/h 2.2 mm Moderate 19
26 May 29.2 °C 58 % 31 km/h 8.7 mm Low 8
27 May 28.1 °C 63 % 32 km/h 15.8 mm Very low 2
28 May after 27.1 °C 60 % 31 km/h 10.4 mm Very low 1

Its twins: fires that started in the same weather

It started with an FWI of 24.7, a minimum humidity of 43% and rain the day before. Fires in the area that started in weather like this since 2016: 19.

FWI at the start 24.7
Minimum humidity 43 %
Days without rain 0
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Metlatónoc fire, May 2022
3,027 ha 12 days FWI 22.5 Min. humidity 42 % 41 km away, in 2022

First rain (1 mm or more) after it ended: 1.2 mm on 13 May.

What happened to them

9 days
median duration
2,738 ha
median area
100 %
went past 1,000 ha
2.6 mm
rain at the end (median; 15 of 19 had it)

It was 6.8 times larger than the median of its twins and lasted 37 days, against 9 days.

None of its 19 twins burned more. The weather on the first day does not explain everything: the wind in the following days, the fuel and the firefighting also count. In 4 of 19, not even 1 mm fell in the ten days after the end: they went out without rain. In the rest, the first rainy day brought a median of 2.6 mm.

This is a bank of analogues: it shows what usually happens, not what will happen. With fewer than 15 twins we give no figures. How we calculate it

How it ended

10.4 mmfirst rain
28 Maythe day after it ended
49km/h · max. gust

It was considered over on 27 May, and on 28 May 10.4 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 15 of 19, with a median of 2.6 mm.

Weather on this page: Open-Meteo.com (CC BY 4.0) · Copernicus Climate Change Service (ERA5)

How a twin is chosen

  • Same area: fires that have already ended, less than 250 km from this one, since 2016.
  • Same start: we compare the FWI on the first day, the minimum humidity that day and the run of days without rain before it. The slider sets how much they may differ.
  • Only pages with final weather data (ERA5 reanalysis) calculated in the same way as this fire’s; agricultural and grass burns and pages with data under review are left out.
  • Fires burning at the same time as this one (a week before or after) are left out: they share the same spell of weather and do not count as a precedent.
  • They are sorted by similarity, and the outlines of the first five are drawn.

How we calculate it

Before and after, from space

Drag the line to compare the same ground before the fire and after it.

Before · 14 Apr 2019
After · 3 Jun 2019

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 · 1,208Every satellite heat detection, one by one, with time, satellite, power and coordinates.
⬇ Download CSV Times in UTC. Each detection is a 375 m pixel: a large fire yields hundreds per pass.
Date and timeSatelliteFRP (MW)LatLon

Other fires nearby

All fires in Mexico

Frequently asked questions

How long did the San Luis Acatlán fire last?
According to the heat detections seen by satellite inside the perimeter, it burned from 21 April 2019 to 27 May 2019 (37 days). The perimeter dates it from 27 April 2019 to 27 May 2019.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 18,688 hectares (186.9 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 4 municipalities: San Luis Acatlán (14,841 ha, 13 %); Ayutla de los Libres (2,812 ha, 2.7 %); Cuautepec (1,773 ha, 5.6 %); Copala (33 ha, 0.1 %).
What was the weather like?
During the fire the temperature reached 31.7 °C, humidity dropped to 28 % and gusts hit 49 km/h. The fire danger index (FWI) reached 41, 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.
How did the fires that started in similar weather in this area end?
Fires less than 250 km away that started since 2016 with a similar FWI, humidity and dry spell: 19. Their median duration was 9 days and their median area 2,738 ha; 100 % went past 1,000 ha. None of its 19 twins burned more. The weather on the first day does not explain everything: the wind in the following days, the fuel and the firefighting also count. In 4 of 19, not even 1 mm fell in the ten days after the end: they went out without rain. In the rest, the first rainy day brought a median of 2.6 mm.

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 · 1 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.
  1. Area: 19,351 → 18,688 ha.

RSS Changes to this page With cross-checks and a citable version

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
What do you think is wrong?

We will only use your email to reply about this report. Privacy. This is not an emergency service: if there is a fire now, call 911.

How we know this
  • Perimeter: GWIS (Copernicus), rebuilt from heat detections rather than mapped on imagery; 3 polygons grouped in this page.
  • Dates adjusted with the VIIRS detections inside the perimeter, which said 27 April 2019 to 27 May 2019. 1,208 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 2020, 100 m cells), summed inside the perimeter: an estimate of what was there, not a damage count.

How we build fire pages: methodology

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.