How long did the Whitmore Fire last?

The official perimeter only gives the start date (4 August 2021). The end comes from the heat detections inside the perimeter: it burned until 16 August 2021 (13 days from 4 August 2021), the last day with detections before more than 10 days in a row without any, so it is approximate.

How much area did it burn?

The official perimeter published by United States agencies (MTBS / NIFC) is 24,253 hectares (242.5 km²). Other tallies, such as daily incident reports, may give slightly different figures.

Which counties burned?

The fire only entered Okanogan (24,098 ha, 1.8 %).

What was the weather like?

During the fire the temperature reached 36.3 °C, humidity dropped to 18 % and gusts hit 50 km/h. The fire danger index (FWI) reached 43, class Very 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.

US · United States · 2021-08-04 → 2021-08-16

Whitmore Fire, August 2021 Okanogan

Out · last detection 16 Aug 2021, 10:31 UTC

The fire started on 4 August 2021 in Okanogan, United States, and satellites saw it burning for 13 days. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 24,253 hectares, spread across a single county.

It is the 15th largest in Washington since 2016 (of 285 with a page). Number 26 in United States in 2021, of 385.

Compare with…

Suggestions: Cold Springs · 2020 Kartar · 2026 Kaiser Canyon · 2026 Pearl Hill · 2026

Burnt area: 24,253ha; official perimeter (MTBS / NIFC)
Duration: ≈ 13days; 4 Aug 2021 – 16 Aug 2021
Counties hit: 1; counties
Started on: 4 Aug; 2021
Heat detections: 759; in a single hotspot: 241 MW
Danger at start: 35; High · FWI index
Average daily power: 726MW; detected power per day, on average

HOTSPOTS BY DAY 4 Aug16 Aug

Play back 16 Aug 2021

How it evolved, day by day

4 Aug 6 Aug 8 Aug 11 Aug 13 Aug 15 Aug

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

50km/h · peak gust

18%lowest humidity

It had gone 2 days without rain (1 mm or more) when it started. Rain came after the fire: 3.8 mm on 17 Aug.

This area had burned before

0% of the perimeter overlaps earlier fires recorded since 2016: 29 ha in 2020.

29 ha Cold Springs fire, September 2020 75,960 ha in total; the hectares shown are those it shares with this fire

How big is it?

It burned the equivalent of 15% of the area of London (243 km² against 1,583 km²).

London boundary: geoBoundaries · Office for National Statistics (Open Government Licence v3.0).

This compares size, not location: both shapes are at the same scale, north up, centred on each other.

What happened to each county

Okanogan where it started

24,098 ha reached on 4 Aug

1.8 %

Burnt area inside each county, from crossing the official 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 area0.89 ha

Residents≈ 40

Inside the perimeter there were about 0.89 hectares of built-up land and about 40 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.

Source: Global Human Settlement Layer (GHS-BUILT-S and GHS-POP R2023A), European Commission Joint Research Centre (JRC), © European Union, CC BY 4.0. Sum inside the perimeter computed by WorldFires. human-settlement.emergency.copernicus.eu

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)
4 Aug	32.7 °C	22 %	28 km/h	0.0 mm	High 35
5 Aug	31.9 °C	25 %	35 km/h	0.0 mm	Very high 38
6 Aug	29.8 °C	31 %	42 km/h	0.0 mm	Very high 39
7 Aug	27.3 °C	34 %	47 km/h	0.0 mm	High 37
8 Aug	21.3 °C	43 %	45 km/h	5.0 mm	Low 6
9 Aug	26.7 °C	33 %	30 km/h	0.0 mm	Moderate 14
10 Aug	31.6 °C	29 %	32 km/h	0.0 mm	High 25
11 Aug	36.3 °C	23 %	30 km/h	0.0 mm	High 35
12 Aug	34.3 °C	18 %	50 km/h	0.0 mm	Very high 42
13 Aug	33.1 °C	21 %	28 km/h	0.0 mm	High 36
14 Aug	35.1 °C	20 %	30 km/h	0.0 mm	Very high 40
15 Aug	34.2 °C	21 %	44 km/h	0.2 mm	Very high 42
16 Aug	29.3 °C	29 %	39 km/h	0.0 mm	Very high 43
17 Aug after	22.5 °C	36 %	56 km/h	3.8 mm	Low 9

Before and after, from space

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

↔

Before · 28 Jul 2021

After · 23 Aug 2021

Before After

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 · 759Every 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 time	Satellite	FRP (MW)	Lat	Lon

Other fires nearby

All fires in United States ›

Frequently asked questions

How long did the Whitmore Fire last?: The official perimeter only gives the start date (4 August 2021). The end comes from the heat detections inside the perimeter: it burned until 16 August 2021 (13 days from 4 August 2021), the last day with detections before more than 10 days in a row without any, so it is approximate.
How much area did it burn?: The official perimeter published by United States agencies (MTBS / NIFC) is 24,253 hectares (242.5 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?: The fire only entered Okanogan (24,098 ha, 1.8 %).
What was the weather like?: During the fire the temperature reached 36.3 °C, humidity dropped to 18 % and gusts hit 50 km/h. The fire danger index (FWI) reached 43, class Very 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 · Emergency number and official warnings ›

Satellite cross-check

NASA FIRMS ↗
NIFC · Fire maps ↗

History of this page Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.

No changes since 24 October 2026.

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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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What really happened?

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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.

How we know this

Perimeter: MTBS (US Geological Survey and US Forest Service), official.
The official perimeter has no end date: the end is the last day with VIIRS detections inside the perimeter before a gap of more than 10 days (150 days at most), so it is approximate. 759 Suomi-NPP VIIRS detections on those dates.
We have not matched this page with any official record.
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.

How we build fire pages: methodology ›

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.

Where it burned