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Gray Hill Fire, August 2020 Millard

Out · last detection 24 Aug 2020, 20:08 UTC

The fire started on 24 August 2020 in Millard, United States, and satellites saw it burning for 1 day. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 2,492 hectares, spread across a single county.

It is the 63th largest in Utah since 2016 (of 165 with a page). Number 159 in United States in 2020, of 441.

The power measured by the satellite is low (11.9 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
2,492ha
official perimeter (MTBS / NIFC)
Duration
1day
24 Aug 2020 – 24 Aug 2020
Municipalities hit
1
counties
Started on
24 Aug
2020
Heat detections
1
in a single hotspot: 12 MW
Danger at start
57
Extreme · FWI index
Energy released
12MW
sum of detected power

Where it burned

HOTSPOTS BY DAY 24 Aug24 Aug

How it evolved, day by day

24

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

The weather it burned in

35°high
37km/h · peak gust
9%lowest humidity

It had gone 32 days without rain (1 mm or more) when it started.

This area had burned before

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

What happened to each town

  1. Millard where it started
    2,481 ha reached on 24 Aug
    0.1 %

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)
24 Aug 34.7 °C 9 % 37 km/h 0.2 mm Extreme 57
25 Aug after 33.5 °C 15 % 51 km/h 0.9 mm Very high 48
26 Aug after 34.8 °C 10 % 43 km/h 0.0 mm Extreme 56
27 Aug after 34.4 °C 4 % 56 km/h 0.0 mm Very extreme 70
28 Aug after 32.5 °C 10 % 36 km/h 0.0 mm Extreme 60
29 Aug after 31.2 °C 11 % 55 km/h 0.0 mm Extreme 66
30 Aug after 33.2 °C 5 % 41 km/h 0.0 mm Extreme 60
31 Aug after 31.4 °C 8 % 64 km/h 0.0 mm Very extreme 75
1 Sept after 24.7 °C 16 % 41 km/h 0.0 mm Very high 50
2 Sept after 30.2 °C 12 % 24 km/h 0.0 mm Very high 43
3 Sept after 32.7 °C 7 % 29 km/h 0.0 mm Extreme 51

Before and after, from space

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

Before · 17 Aug 2020
After · 31 Aug 2020

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 · 1Every 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 Gray Hill fire last?
It burned between 24 August 2020 and 24 August 2020: 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 2,492 hectares (24.9 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?
The fire only entered Millard (2,481 ha, 0.1 %).
What was the weather like?
During the fire the temperature reached 34.7 °C, humidity dropped to 9 % and gusts hit 37 km/h. The fire danger index (FWI) reached 57, class 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.