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Walnut Fire, June 2021 Cochise

Out · last detection 21 Jun 2021, 21:02 UTC

The fire started on 20 June 2021 in Cochise, United States, and satellites saw it burning for 1 day. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 4,282 hectares, spread across a single county.

It is the 80th largest in Arizona since 2016 (of 380 with a page). Number 100 in United States in 2021, of 385.

Burnt area
4,282ha
official perimeter (MTBS / NIFC)
Duration
1day
20 Jun 2021 – 20 Jun 2021
Municipalities hit
1
counties
Started on
20 Jun
2021
Heat detections
274
in a single hotspot: 135 MW
Danger at start
85
Very extreme · FWI index
Energy released
2.4GW
sum of detected power

Where it burned

21 Jun 2021
HOTSPOTS BY DAY 20 Jun20 Jun

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

36°high
60km/h · peak gust
11%lowest humidity

It had gone 53 days without rain (1 mm or more) when it started. Rain came after the fire: 1.8 mm on 1 Jul.

This area had burned before

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

What happened to each town

  1. Cochise where it started
    4,303 ha reached on 20 Jun
    0.3 %

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 Jun 35.9 °C 11 % 60 km/h 0.0 mm Very extreme 85
21 Jun after 33.9 °C 13 % 50 km/h 0.0 mm Extreme 69
22 Jun after 32.4 °C 16 % 46 km/h 0.0 mm Extreme 67
23 Jun after 30.3 °C 28 % 43 km/h 0.1 mm Very high 49
24 Jun after 30.2 °C 25 % 37 km/h 4.0 mm Moderate 14
25 Jun after 32.8 °C 16 % 40 km/h 0.0 mm Very high 45
26 Jun after 32.5 °C 11 % 28 km/h 0.0 mm Very high 49
27 Jun after 32.7 °C 16 % 46 km/h 1.5 mm Very high 43
28 Jun after 28.3 °C 27 % 44 km/h 0.0 mm Very high 44
29 Jun after 28.2 °C 22 % 37 km/h 0.0 mm Very high 38
30 Jun after 28.1 °C 30 % 33 km/h 0.2 mm Very high 44
1 Jul after 29.4 °C 25 % 28 km/h 1.8 mm Moderate 20

Before and after, from space

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

Before · 13 Jun 2021
After · 27 Jun 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 · 274Every 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 Walnut fire last?
It burned between 20 June 2021 and 20 June 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 4,282 hectares (42.8 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?
The fire only entered Cochise (4,303 ha, 0.3 %).
What was the weather like?
During the fire the temperature reached 35.9 °C, humidity dropped to 11 % and gusts hit 60 km/h. The fire danger index (FWI) reached 85, class Very extreme.
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.

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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.