Valle de Bravo fire, April 2021
Valle de Bravo, Donato Guerra, Ixtapan del Oro
Out · last detection 28 Apr 2021, 08:19 UTC
The fire started on 19 April 2021 in Valle de Bravo, Mexico, and satellites saw it burning for 10 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 2,594 hectares from heat detections, spread across 3 municipalities.
It is the 14th largest in México since 2016 (of 26 with a page). Number 141 in Mexico in 2021, of 294.
matches the official recordwith caveatssatellite onlymodel
When copying, the sentence is
Tick the figures you want: they make up the lede and the CSV.
Burned area
with caveats
2,594ha
Perimeter published by GWIS (Copernicus).
This page2,594CONAFOR1,002
Source
GWIS (Copernicus)
Date
19 Apr 2021 – 28 Apr 2021
+− cross-check
CONAFOR: 1,002 ha (matched records: 2). Difference between the page and the official record: +158.9%. Matched on 8 November 2026. The two figures differ a lot, so these may not be exactly the same fire: take them as nearby records.
Duration by satellite
satellite only
10days
19 Apr 2021 to 28 Apr 2021: first and last day with fire on the page.
Source
GWIS (Copernicus) · NASA FIRMS · VIIRS
Date
last detection: 28 Apr 2021, 08:19 UTC
+− cross-check
Satellites pass a few times a day and cloud or smoke can hide the fire: a lack of detections is not an official extinction. Each country’s emergency service declares a fire contained or out.
Start
satellite only
19 Apr 2021
First day with fire seen by the satellites or the perimeter.
Source
GWIS (Copernicus) · NASA FIRMS · VIIRS
Date
19 Apr 2021
+− cross-check
The two figures differ a lot, so these may not be exactly the same fire: take them as nearby records.
Hotspots
satellite only
79
VIIRS detections at 375 m. Most intense hotspot: 117 MW.
Source
NASA FIRMS · VIIRS (Suomi NPP)
Date
19 Apr 2021 – 28 Apr 2021
+− cross-check
There is no official record to compare with. Each hotspot is a pixel detected in one satellite pass, not a separate fire.
The worst day
satellite only
845MW
Total radiative power on 21 April 2021; hotspots that day: 45.
Source
NASA FIRMS · VIIRS (FRP)
Date
21 Apr 2021
+− cross-check
Fire radiative power (FRP) measures the energy the fire gives off when the satellite passes. Added up by day, it compares intensity, not area.
Danger at the start
model
59.7FWI · extreme
Fire Weather Index (Canadian system) computed by WorldFires for the day the fire started. Consecutive days without rain before: 60.
This is an index computed from weather model data, not a measurement of the fire nor an official warning. Danger warnings are issued by each country’s authority. Emergency number and official warnings ›
Weather during the fire
model
29.3°C · 24% RH
High of 29.3 °C and minimum humidity of 24% on 27 April 2021; gusts of 47 km/h on 24 April 2021.
These are model values for a cell of about 25 km, not from a weather station: they may differ from what was measured on the ground.
Living inside
model
≈ 450people
Estimated residents inside the perimeter and 6.8 ha of built-up area (100 m grid, epoch 2020).
Source
GHSL R2023A · JRC
Date
calculated on 24 October 2026
+− cross-check
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.
ⓘThis page’s change log has been kept since 24 October 2026: every night what it publishes is compared and the difference is logged. Anything earlier is reconstructed from each source’s date and marked as reconstructed.
Show
· reconstructedofficial
Matched with the official CONAFOR record
Nearby records with very different figures: 1,002 ha (records: 2).
A version keeps the area, dates, name and official record; the area as it was logged (changes under 2% are not logged). The map, hotspots and weather always show today’s data.
Citation
A lede of about 60 words figures only, no adjectives
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 area6.8ha
Residents≈ 450
Inside the perimeter there were about 6.8 hectares of built-up land and about 450 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.
According to CONAFOR, 2 fires started inside this perimeter on these dates, totalling 1,002 ha (the satellite measured 2,594 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.
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)
It started with an FWI of 59.7, a minimum humidity of 12% and more than two months without rain. Fires in the area that started in weather like this since 2016: 26.
FWI at the start59.7
Minimum humidity12 %
Days without rain60+
this firechosen twinsrest of the area
Almost identicalSimilar
Outlines of the closest twins
This fire · Valle de Bravo fire, April 2021
2,594 ha10 daysFWI 59.7Min. humidity 12 %
Nocupétaro fire, May 2024
2,655 ha5 daysFWI 58.0Min. humidity 16 %101 km away, in 2024
First rain (1 mm or more) after it ended: none in the following ten days.
It burned an area similar to its twins (2,594 ha against a median of 2,446 ha) and lasted 10 days, against 11 days.
In 18 of 26, 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 2.4 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
1.3 mmfirst rain
7 May9 days after it ended
47km/h · max. gust
It was considered over on 28 Apr, and on 7 May 1.3 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 8 of 26, with a median of 2.4 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.
According to the heat detections seen by satellite inside the perimeter, it burned from 19 April 2021 to 28 April 2021 (10 days). The perimeter dates it from 20 April 2021 to 25 April 2021.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 2,594 hectares (25.9 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 3 municipalities: Valle de Bravo (2,084 ha, 5.2 %); Donato Guerra (436 ha, 2.3 %); Ixtapan del Oro (90 ha, 0.9 %).
What was the weather like?
During the fire the temperature reached 29.3 °C, humidity dropped to 10 % and gusts hit 47 km/h. The fire danger index (FWI) reached 60, 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.
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: 26. Their median duration was 11 days and their median area 2,446 ha; 100 % went past 1,000 ha. In 18 of 26, 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 2.4 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.
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 errorHow 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 20 April 2021 to 25 April 2021. 79 Suomi-NPP VIIRS detections on those dates.
Compared with CONAFOR: 1,002 official ha against 2,594 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.
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.