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MX · Mexico · –

San Luis Acatlán fire, 13 April 2018 San Luis Acatlán

Out · last detection 19 Apr 2018, 19:48 UTC

The fire started on 13 April 2018 in San Luis Acatlán, Mexico, and satellites saw it burning for 7 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 1,789 hectares from heat detections, spread across a single municipality.

It is the 470th largest in Guerrero since 2016 (of 582 with a page). Number 177 in Mexico in 2018, of 233.

The power measured by the satellite is low (11.6 MW in the strongest hotspot), more typical of grass or stubble burning, or a slow surface fire, than of a large crown fire.

Burnt area
1,789ha
GWIS perimeter (Copernicus)
Duration
7days
13 Apr 2018 – 19 Apr 2018
Municipalities hit
1
municipalities
Started on
13 Apr
2018
Heat detections
85
in a single hotspot: 12 MW
Danger at start
22
High · FWI index
Average daily power
50MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 13 Apr19 Apr
19 Apr 2018

How it evolved, day by day

13 Apr 2018 · 33 MW · 5 14 Apr 2018 · 75 MW · 11 15 Apr 2018 · 17 MW · 6 16 Apr 2018 · 57 MW · 16 17 Apr 2018 · 48 MW · 14 18 Apr 2018 · 99 MW · 26 19 Apr 2018 · 24 MW · 7
13 Apr 15 Apr 18 Apr

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
42km/h · peak gust
35%lowest humidity

It had gone one day without rain (1 mm or more) when it started.

This area had burned before

7% of the perimeter overlaps earlier fires recorded since 2016: 130 ha in 2017.

How big is it?

10 km
It burned the equivalent of 1.1% of the area of London (18 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
    1,799 ha reached on 13 Apr
    1.6 %

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 area< 0.1 ha
Residents< 20

Inside 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

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)
13 Apr 30.5 °C 42 % 41 km/h 0.0 mm High 22
14 Apr 30.8 °C 35 % 40 km/h 0.0 mm High 26
15 Apr 31.2 °C 39 % 41 km/h 0.0 mm High 25
16 Apr 32.4 °C 35 % 36 km/h 0.0 mm High 26
17 Apr 31.6 °C 36 % 41 km/h 0.0 mm High 28
18 Apr 31.3 °C 37 % 42 km/h 0.0 mm High 29
19 Apr 31.4 °C 38 % 39 km/h 0.0 mm High 27
20 Apr after 32.0 °C 36 % 40 km/h 0.0 mm High 29
21 Apr after 32.7 °C 35 % 45 km/h 0.0 mm High 30
22 Apr after 32.6 °C 38 % 40 km/h 0.0 mm High 30
23 Apr after 33.1 °C 37 % 36 km/h 0.0 mm High 32
24 Apr after 32.2 °C 37 % 37 km/h 0.0 mm High 29
25 Apr after 32.6 °C 40 % 38 km/h 0.4 mm High 29
26 Apr after 31.5 °C 41 % 36 km/h 0.2 mm High 29
27 Apr after 31.6 °C 36 % 39 km/h 0.0 mm High 30
28 Apr after 32.4 °C 37 % 37 km/h 0.0 mm High 30
29 Apr after 32.5 °C 41 % 36 km/h 0.1 mm High 29

Its twins: fires that started in the same weather

It started with an FWI of 22.1, a minimum humidity of 42% and 1 day without rain. Fires in the area that started in weather like this since 2016: 16.

FWI at the start 22.1
Minimum humidity 42 %
Days without rain 1
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Metlatónoc fire, May 2022
3,936 ha 13 days FWI 21.8 Min. humidity 42 % 50 km away, in 2022

First rain (1 mm or more) after it ended: 3.4 mm on 24 May.

What happened to them

10 days
median duration
3,008 ha
median area
100 %
went past 1,000 ha
2.1 mm
rain at the end (median; 13 of 16 had it)

It stayed below its twins: 1,789 ha against a median of 3,008 ha. It lasted 7 days, against 10 days.

In 3 of 16, 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 2.1 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

—first rain
—no rain in ten days
42km/h · max. gust

It was considered over on 19 Apr, and not even 1 mm fell in the following ten days: it went out without rain. Twins with rain when they ended: 13 of 16, with a median of 2.1 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 · 6 Apr 2018
After · 26 Apr 2018

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 · 85Every 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?
GWIS (Copernicus) dates it between 13 April 2018 and 19 April 2018: 7 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 1,789 hectares (17.9 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire only entered San Luis Acatlán (1,799 ha, 1.6 %).
What was the weather like?
During the fire the temperature reached 32.4 °C, humidity dropped to 35 % and gusts hit 42 km/h. The fire danger index (FWI) reached 29, class 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: 16. Their median duration was 10 days and their median area 3,008 ha; 100 % went past 1,000 ha. In 3 of 16, 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 2.1 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 Changes in area, dates, name, official record or merged pages, compared every night 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
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.
  • Dates from the perimeter: the VIIRS detections inside it did not change them. 85 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.