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Russell Mountain Fire, August 2022 Boundary

Out · last detection 25 Oct 2022, 09:34 UTC

The fire started on 17 August 2022 in Boundary, United States, and satellites saw it burning for 70 days. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 10,564 hectares, spread across a single county.

It is the 37th largest in Idaho since 2016 (of 379 with a page). Number 57 in United States in 2022, of 493.

Burnt area
10,564ha
official perimeter (MTBS / NIFC)
Duration
≈ 70days
17 Aug 2022 – 25 Oct 2022
Counties hit
1
counties
Started on
17 Aug
2022
Heat detections
3,036
in a single hotspot: 303 MW
Danger at start
35
High · FWI index
Average daily power
500MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 17 Aug25 Oct
25 Oct 2022

How it evolved, day by day

17 Aug 2022 · 175 MW · 14 18 Aug 2022 · 150 MW · 17 19 Aug 2022 · 866 MW · 48 21 Aug 2022 · 50 MW · 3 22 Aug 2022 · 15 MW · 7 23 Aug 2022 · 4 MW · 2 24 Aug 2022 · 10 MW · 2 26 Aug 2022 · 25 MW · 5 27 Aug 2022 · 11 MW · 7 29 Aug 2022 · 45 MW · 6 30 Aug 2022 · 797 MW · 19 31 Aug 2022 · 1,010 MW · 45 1 Sept 2022 · 6,478 MW · 251 2 Sept 2022 · 2,906 MW · 311 3 Sept 2022 · 837 MW · 222 4 Sept 2022 · 1,849 MW · 275 5 Sept 2022 · 1,859 MW · 257 6 Sept 2022 · 767 MW · 204 7 Sept 2022 · 3,839 MW · 293 8 Sept 2022 · 1,329 MW · 163 9 Sept 2022 · 1,192 MW · 195 10 Sept 2022 · 506 MW · 113 11 Sept 2022 · 228 MW · 104 12 Sept 2022 · 34 MW · 8 13 Sept 2022 · 102 MW · 44 14 Sept 2022 · 50 MW · 16 19 Sept 2022 · 6 MW · 2 20 Sept 2022 · 45 MW · 14 21 Sept 2022 · 141 MW · 26 23 Sept 2022 · 1 MW · 1 24 Sept 2022 · 6 MW · 5 25 Sept 2022 · 16 MW · 7 26 Sept 2022 · 10 MW · 8 27 Sept 2022 · 101 MW · 37 28 Sept 2022 · 320 MW · 60 4 Oct 2022 · 10 MW · 4 5 Oct 2022 · 29 MW · 2 6 Oct 2022 · 0 MW · 1 7 Oct 2022 · 1 MW · 1 8 Oct 2022 · 3 MW · 4 9 Oct 2022 · 13 MW · 10 10 Oct 2022 · 5 MW · 4 11 Oct 2022 · 45 MW · 22 12 Oct 2022 · 19 MW · 8 13 Oct 2022 · 26 MW · 17 14 Oct 2022 · 19 MW · 13 15 Oct 2022 · 28 MW · 12 16 Oct 2022 · 50 MW · 17 17 Oct 2022 · 35 MW · 19 18 Oct 2022 · 49 MW · 21 19 Oct 2022 · 275 MW · 52 20 Oct 2022 · 81 MW · 37 25 Oct 2022 · 7 MW · 1
17 Aug 1 Sept 11 Sept 27 Sept 13 Oct

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

The weather it burned in

34°high
58km/h · peak gust
11%lowest humidity

It had gone 4 days without rain (1 mm or more) when it started. Rain came after the fire: 6.3 mm on 26 Oct.

This area had burned before

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

How big is it?

10 km
It burned the equivalent of 6.7% of the area of London (106 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

  1. Boundary where it started
    10,576 ha reached on 17 Aug
    3.2 %

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 area< 0.1 ha
Residents< 20

Inside the perimeter there was no noticeable built-up land and almost nobody lived there (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)

Started with Very dry air: 40 % of the area in United States

Day High Min. humidity Peak gust Rain Danger (FWI)
17 Aug 32.7 °C 14 % 20 km/h 0.0 mm High 35
18 Aug 34.0 °C 15 % 21 km/h 0.0 mm Very high 38
19 Aug 32.9 °C 18 % 20 km/h 0.4 mm High 37
20 Aug 28.6 °C 31 % 30 km/h 0.6 mm High 30
21 Aug 28.3 °C 24 % 33 km/h 0.0 mm High 32
22 Aug 28.1 °C 24 % 33 km/h 0.0 mm High 33
23 Aug 27.4 °C 20 % 22 km/h 0.4 mm High 33
24 Aug 23.9 °C 46 % 46 km/h 1.7 mm Low 11
25 Aug 23.3 °C 44 % 28 km/h 1.8 mm Low 7
26 Aug 25.4 °C 40 % 40 km/h 0.9 mm Moderate 12
27 Aug 18.8 °C 32 % 51 km/h 0.2 mm Moderate 21
28 Aug 21.1 °C 29 % 35 km/h 0.0 mm High 23
29 Aug 26.1 °C 25 % 23 km/h 0.0 mm High 25
30 Aug 29.8 °C 19 % 19 km/h 0.0 mm High 31
31 Aug 31.6 °C 17 % 20 km/h 0.0 mm High 32
1 Sept 29.7 °C 18 % 35 km/h 0.0 mm High 36
2 Sept 30.1 °C 20 % 24 km/h 0.0 mm High 34
3 Sept 28.4 °C 24 % 58 km/h 0.0 mm Very high 41
4 Sept 25.5 °C 26 % 44 km/h 0.0 mm High 36
5 Sept 23.7 °C 25 % 50 km/h 0.0 mm High 37
6 Sept 26.3 °C 18 % 23 km/h 0.0 mm High 31
7 Sept 26.3 °C 23 % 46 km/h 0.0 mm High 36
8 Sept 22.1 °C 16 % 28 km/h 0.0 mm High 34
9 Sept 18.6 °C 24 % 43 km/h 0.0 mm High 34
10 Sept 22.6 °C 19 % 17 km/h 0.0 mm High 30
11 Sept 22.6 °C 23 % 27 km/h 0.0 mm High 31
12 Sept 22.1 °C 29 % 26 km/h 0.6 mm High 24
13 Sept 22.7 °C 32 % 26 km/h 0.4 mm High 25
14 Sept 16.5 °C 49 % 27 km/h 5.4 mm Very low 2
15 Sept 18.3 °C 40 % 23 km/h 0.7 mm Very low 5
16 Sept 16.1 °C 52 % 44 km/h 1.2 mm Low 6
17 Sept 17.0 °C 32 % 20 km/h 0.0 mm Moderate 11
18 Sept 19.6 °C 29 % 22 km/h 0.0 mm Moderate 18
19 Sept 18.8 °C 27 % 38 km/h 0.0 mm High 22
20 Sept 17.3 °C 27 % 42 km/h 0.0 mm High 24
21 Sept 20.7 °C 22 % 35 km/h 0.0 mm High 26
22 Sept 12.4 °C 51 % 37 km/h 0.8 mm Moderate 12
23 Sept 14.4 °C 47 % 37 km/h 0.1 mm Moderate 15
24 Sept 20.0 °C 31 % 24 km/h 0.0 mm Moderate 18
25 Sept 22.3 °C 28 % 17 km/h 0.0 mm Moderate 21
26 Sept 24.8 °C 19 % 22 km/h 0.0 mm High 26
27 Sept 27.4 °C 11 % 21 km/h 0.0 mm High 34
28 Sept 26.0 °C 23 % 34 km/h 0.0 mm High 34
29 Sept 17.9 °C 40 % 28 km/h 4.4 mm Very low 4
30 Sept 15.0 °C 67 % 18 km/h 2.9 mm Very low 1
1 Oct 22.6 °C 29 % 27 km/h 0.0 mm Low 6
2 Oct 22.2 °C 30 % 20 km/h 0.0 mm Moderate 13
3 Oct 23.3 °C 32 % 20 km/h 0.0 mm Moderate 17
4 Oct 23.3 °C 30 % 18 km/h 0.0 mm Moderate 19
5 Oct 22.8 °C 22 % 16 km/h 0.0 mm Moderate 21
6 Oct 22.3 °C 28 % 23 km/h 0.0 mm High 23
7 Oct 21.9 °C 20 % 21 km/h 0.0 mm High 25
8 Oct 21.5 °C 18 % 13 km/h 0.0 mm High 24
9 Oct 21.4 °C 23 % 19 km/h 0.0 mm High 25
10 Oct 19.4 °C 32 % 54 km/h 0.0 mm High 29
11 Oct 17.9 °C 13 % 46 km/h 0.0 mm High 30
12 Oct 19.1 °C 20 % 26 km/h 0.0 mm High 27
13 Oct 19.8 °C 19 % 17 km/h 0.0 mm High 26
14 Oct 19.7 °C 21 % 19 km/h 0.0 mm High 27
15 Oct 19.3 °C 24 % 21 km/h 0.0 mm High 27
16 Oct 20.3 °C 13 % 17 km/h 0.0 mm High 29
17 Oct 20.8 °C 15 % 14 km/h 0.0 mm High 28
18 Oct 19.7 °C 14 % 17 km/h 0.0 mm High 29
19 Oct 19.9 °C 20 % 23 km/h 0.0 mm High 30
20 Oct 14.2 °C 44 % 32 km/h 0.1 mm High 22
21 Oct 8.5 °C 80 % 38 km/h 9.4 mm Very low 0
22 Oct 2.2 °C 88 % 22 km/h 10.9 mm Very low 0
23 Oct 7.0 °C 42 % 26 km/h 1.2 mm Very low 0
24 Oct 2.1 °C 86 % 42 km/h 7.8 mm Very low 0
25 Oct 3.7 °C 81 % 42 km/h 5.8 mm Very low 0
26 Oct after 2.9 °C 81 % 38 km/h 6.3 mm Very low 0

Its twins: fires that started in the same weather

It started with an FWI of 35.3, a minimum humidity of 14% and 4 days without rain. Fires in the area that started in weather like this since 2016: 24.

FWI at the start 35.3
Minimum humidity 14 %
Days without rain 4
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

East Fork Fire, July 2023
2,254 ha 7 days FWI 35.0 Min. humidity 14 % 128 km away, in 2023

First rain (1 mm or more) after it ended: none in the following ten days.

What happened to them

11 days
median duration
2,198 ha
median area
79 %
went past 1,000 ha
2.8 mm
rain at the end (median; 22 of 24 had it)

It was 4.8 times larger than the median of its twins and lasted 70 days, against 11 days.

Only 4 of its 24 twins burned more. The weather on the first day does not explain everything: the wind in the following days, the fuel and the firefighting also count. In 2 of 24, not even 1 mm fell in the ten days after the end: they went out without rain. In the rest, the first rainy day brought a median of 2.8 mm.

This is a bank of analogues: it shows what usually happens, not what will happen. With fewer than 15 twins we give no figures. How we calculate it

How it ended

6.3 mmfirst rain
26 Octthe day after it ended
58km/h · max. gust

It was considered over on 25 Oct, and on 26 Oct 6.3 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 22 of 24, with a median of 2.8 mm.

Weather on this page: Open-Meteo.com (CC BY 4.0) · Copernicus Climate Change Service (ERA5)

How a twin is chosen

  • Same area: fires that have already ended, less than 250 km from this one, since 2016.
  • Same start: we compare the FWI on the first day, the minimum humidity that day and the run of days without rain before it. The slider sets how much they may differ.
  • Only pages with final weather data (ERA5 reanalysis) calculated in the same way as this fire’s; agricultural and grass burns and pages with data under review are left out.
  • Fires burning at the same time as this one (a week before or after) are left out: they share the same spell of weather and do not count as a precedent.
  • They are sorted by similarity, and the outlines of the first five are drawn.

How we calculate it

Before and after, from space

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

Before · 10 Aug 2022
After · 1 Nov 2022

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 22 August 2022 the air beside the fire reached 22 µg/m³ of PM2.5, but no daily average passed the WHO guideline (15).

PM2.5 peak22 µg/m³
Days over the guideline0 days
PM1032 µg/m³
Optical depth0.31
22 Aug24 Aug26 Aug
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 · 3,036Every 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 Russell Mountain Fire last?
The official perimeter only gives the start date (24 August 2022). The end comes from the heat detections inside the perimeter: it burned until 25 October 2022 (70 days from 17 August 2022), 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 10,564 hectares (105.6 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?
The fire only entered Boundary (10,576 ha, 3.2 %).
What was the weather like?
During the fire the temperature reached 34.0 °C, humidity dropped to 11 % and gusts hit 58 km/h. The fire danger index (FWI) reached 41, 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.
How did the fires that started in similar weather in this area end?
Fires less than 250 km away that started since 2016 with a similar FWI, humidity and dry spell: 24. Their median duration was 11 days and their median area 2,198 ha; 79 % went past 1,000 ha. Only 4 of its 24 twins burned more. The weather on the first day does not explain everything: the wind in the following days, the fuel and the firefighting also count. In 2 of 24, not even 1 mm fell in the ten days after the end: they went out without rain. In the rest, the first rainy day brought a median of 2.8 mm.

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

History of this page · 1 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.
  1. Last day with fire: 20 October 2022 → 25 October 2022.

RSS Changes to this page With cross-checks and a citable version

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.

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. 3,036 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.