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Willow Fire, May 2023 Coconino

Out · last measured on 21 May 2023

The fire started on 21 May 2023 in Coconino, United States, and satellites saw it burning for 1 day. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 534 hectares, spread across a single county.

It is the 330th largest in Arizona since 2016 (of 380 with a page). Number 253 in United States in 2023, of 305.

Burnt area
534ha
official perimeter (MTBS / NIFC)
Duration
1day
21 May 2023 – 21 May 2023
Municipalities hit
1
counties
Started on
21 May
2023
Heat detections
47
in a single hotspot: 19 MW
Danger at start
6
Low · FWI index

Where it burned

HOTSPOTS BY DAY 21 May21 May

The weather it burned in

23°high
61km/h · peak gust
14%lowest humidity

It had gone 0 days without rain (1 mm or more) when it started.

This area had burned before

2% of the perimeter overlaps earlier fires recorded since 2016: 12 ha in 2018.

What happened to each town

  1. Coconino where it started
    527 ha reached on 24 May
    0.0 %

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)
21 May 20.7 °C 28 % 27 km/h 0.2 mm Low 6
22 May after 21.7 °C 26 % 32 km/h 0.7 mm Low 11
23 May after 23.4 °C 19 % 37 km/h 0.3 mm Moderate 18
24 May after 21.9 °C 20 % 48 km/h 0.0 mm Moderate 21
25 May after 22.4 °C 14 % 55 km/h 0.0 mm High 28
26 May after 20.5 °C 15 % 61 km/h 0.0 mm High 30
27 May after 21.1 °C 14 % 56 km/h 0.0 mm High 30
28 May after 22.7 °C 14 % 49 km/h 0.0 mm High 28
29 May after 22.8 °C 14 % 53 km/h 0.0 mm High 31
30 May after 22.7 °C 15 % 52 km/h 0.0 mm High 32
31 May after 20.0 °C 15 % 65 km/h 0.0 mm Very high 38
1 Jun after 20.0 °C 22 % 35 km/h 0.0 mm High 26
2 Jun after 20.5 °C 30 % 29 km/h 0.5 mm High 22
3 Jun after 22.9 °C 25 % 24 km/h 0.3 mm High 21
4 Jun after 23.2 °C 20 % 29 km/h 0.3 mm High 24
5 Jun after 25.7 °C 16 % 51 km/h 0.0 mm High 36

Before and after, from space

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

Before · 14 May 2023
After · 28 May 2023

If the day is cloudy, change the date: each satellite passes once a day. In false colour the burnt ground looks brown or red.

The smoke

CAMS · Copernicus

On 19 May 2023 the air beside the fire reached 12 µg/m³ of PM2.5, but no daily average passed the WHO guideline (15).

PM2.5 peak12 µg/m³
Days over the guideline0 days
PM1018 µg/m³
Optical depth0.33
192021222324
Good Fair Moderate Poor Very poor Extremely poor

Particles from the Copernicus CAMS model at the centre of the perimeter; these are not measurements in each town. The pale bar is the worst hour, the solid one the daily average.

Open-Meteo.com (CC BY 4.0) · Copernicus Atmosphere Monitoring Service (CAMS)

Detections table · 47Every 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 Willow fire last?
It burned between 21 May 2023 and 21 May 2023: 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 534 hectares (5.3 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?
The fire only entered Coconino (527 ha, 0.0 %).
What was the weather like?
During the fire the temperature reached 23.4 °C, humidity dropped to 14 % and gusts hit 61 km/h. The fire danger index (FWI) reached 30, 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
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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.