Skip to content
worldfires
US · United States · →

Johnson Fire, May 2021 Catron, Grant

Out · last detection 21 May 2021, 09:24 UTC

The fire started on 20 May 2021 in Grant, United States, and satellites saw it burning for 1 day. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 38,793 hectares, spread across 2 counties.

It is the 3th largest in New Mexico since 2016 (of 204 with a page). Number 17 in United States in 2021, of 385.

Burnt area
38,793ha
official perimeter (MTBS / NIFC)
Duration
1day
20 May 2021 – 20 May 2021
Municipalities hit
2
counties
Started on
20 May
2021
Heat detections
3,673
in a single hotspot: 261 MW
Danger at start
18
Moderate · FWI index
Energy released
728MW
sum of detected power

Where it burned

21 May 2021
HOTSPOTS BY DAY 20 May20 May

How it evolved, day by day

2021

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

The weather it burned in

22°high
95km/h · peak gust
8%lowest humidity

It had gone 0 days without rain (1 mm or more) when it started. Rain came after the fire: 9.3 mm on 1 Jun.

This area had burned before

No earlier perimeters overlap this fire since 2016, when the satellite record begins.

What happened to each town

  1. Catron
    19,450 ha reached on 20 May
    1.1 %
  2. Grant where it started
    19,404 ha reached on 25 May
    1.9 %

Burnt area inside each county, from crossing the official perimeter with administrative boundaries. The distance is from the town centre to the nearest fire: staying a kilometre away does not mean it reached the houses.

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)
20 May 21.0 °C 18 % 61 km/h 0.0 mm Moderate 18
21 May after 13.2 °C 31 % 70 km/h 5.9 mm Very low 3
22 May after 19.5 °C 18 % 95 km/h 0.1 mm Moderate 18
23 May after 17.6 °C 10 % 56 km/h 0.0 mm High 23
24 May after 20.0 °C 10 % 50 km/h 0.0 mm High 26
25 May after 21.7 °C 8 % 47 km/h 0.0 mm High 29
26 May after 21.6 °C 10 % 54 km/h 0.0 mm High 32
27 May after 22.2 °C 13 % 56 km/h 0.2 mm High 34
28 May after 23.6 °C 9 % 49 km/h 0.0 mm High 33
29 May after 23.4 °C 8 % 59 km/h 0.0 mm High 38
30 May after 22.4 °C 9 % 53 km/h 0.0 mm High 37
31 May after 21.7 °C 14 % 41 km/h 0.2 mm High 32
1 Jun after 18.7 °C 33 % 37 km/h 9.3 mm Very low 2

Before and after, from space

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

Before · 13 May 2021
After · 27 May 2021

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 · 3,673Every 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 United States ›

Frequently asked questions

How long did the Johnson fire last?
It burned between 20 May 2021 and 20 May 2021: 1 day, according to the start date recorded by United States agencies (MTBS / NIFC) and the heat detections seen by satellite.
How much area did it burn?
The official perimeter published by United States agencies (MTBS / NIFC) is 38,793 hectares (387.9 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?
The fire entered 2 counties: Catron (19,450 ha, 1.1 %); Grant (19,404 ha, 1.9 %).
What was the weather like?
During the fire the temperature reached 22.2 °C, humidity dropped to 8 % and gusts hit 95 km/h. The fire danger index (FWI) reached 34, class High.
Where does this data come from?
From the official burnt perimeter of United States agencies (MTBS / NIFC, public domain), NASA FIRMS VIIRS hotspots and the administrative boundaries of United States. 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

Satellite cross-check

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.

Where this data comes from

The perimeter is official and in the public domain. For past years it comes from MTBS (Monitoring Trends in Burn Severity), run by the U.S. Geological Survey and the USDA Forest Service, which map it on Landsat and Sentinel-2 imagery. For the current and last year it comes from WFIGS at the National Interagency Fire Center (NIFC): incident perimeters mapped by fire crews, aircraft and imagery. Heat detections come from the VIIRS sensors aboard Suomi-NPP and NOAA-20, distributed by NASA FIRMS at 375 m resolution. County boundaries come from geoBoundaries ADM2 (Public Domain). The area per county is computed by WorldFires by crossing the perimeter with those boundaries, so it may differ slightly from official figures.