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US · United States · –

Blodgett Lake Fire, August 2022 Ravalli, Idaho

Out · last detection 12 Sept 2022, 19:27 UTC

The fire started on 25 August 2022 in Ravalli, United States, and satellites saw it burning for 19 days. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 965 hectares, spread across 2 counties.

It is the 187th largest in Montana since 2016 (of 302 with a page). Number 316 in United States in 2022, of 493.

Burnt area
965ha
official perimeter (MTBS / NIFC)
Duration
≈ 19days
25 Aug 2022 – 12 Sept 2022
Counties hit
2
counties
Started on
25 Aug
2022
Heat detections
199
in a single hotspot: 200 MW
Danger at start
5
Very low · FWI index
Average daily power
2.1GW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 25 Aug12 Sept
12 Sept 2022

How it evolved, day by day

9 Sept 2022 · 341 MW · 11 10 Sept 2022 · 425 MW · 17 11 Sept 2022 · 6,267 MW · 99 12 Sept 2022 · 1,323 MW · 72
9 Sept 10 Sept 11 Sept 12 Sept

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

The weather it burned in

32°high
70km/h · peak gust
12%lowest humidity

It had gone 0 days without rain (1 mm or more) when it started. Rain came after the fire: 1.7 mm on 13 Sept.

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 0.6% of the area of London (9.6 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. Ravalli where it started
    946 ha reached on 9 Sept
    0.2 %
  2. 20 ha reached on 12 Sept
    0.0 %

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 area1.4 ha
Residents< 20

Inside the perimeter there were about 1.4 hectares of 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)

Day High Min. humidity Peak gust Rain Danger (FWI)
25 Aug 24.9 °C 39 % 43 km/h 2.5 mm Very low 5
26 Aug 24.0 °C 34 % 47 km/h 0.9 mm Low 10
27 Aug 19.9 °C 38 % 63 km/h 0.0 mm Moderate 16
28 Aug 20.4 °C 31 % 41 km/h 0.0 mm Moderate 16
29 Aug 27.5 °C 21 % 23 km/h 0.0 mm Moderate 20
30 Aug 30.2 °C 14 % 32 km/h 0.0 mm High 30
31 Aug 31.4 °C 15 % 31 km/h 0.0 mm High 29
1 Sept 28.3 °C 18 % 43 km/h 0.0 mm High 33
2 Sept 30.9 °C 13 % 27 km/h 0.0 mm High 30
3 Sept 30.4 °C 17 % 51 km/h 0.1 mm High 37
4 Sept 28.5 °C 15 % 46 km/h 0.0 mm High 38
5 Sept 26.7 °C 16 % 50 km/h 0.0 mm Very high 39
6 Sept 32.0 °C 14 % 44 km/h 0.0 mm Very high 39
7 Sept 28.1 °C 19 % 70 km/h 1.0 mm High 33
8 Sept 19.1 °C 12 % 54 km/h 0.0 mm High 34
9 Sept 16.6 °C 27 % 38 km/h 0.0 mm High 28
10 Sept 23.5 °C 15 % 22 km/h 0.0 mm High 28
11 Sept 25.4 °C 15 % 38 km/h 0.0 mm High 32
12 Sept 25.9 °C 14 % 31 km/h 0.0 mm High 33
13 Sept after 16.6 °C 45 % 21 km/h 1.7 mm Low 6

Its twins: fires that started in the same weather

It started with an FWI of 4.6, a minimum humidity of 39% and rain the day before. Fires in the area that started in weather like this since 2016: 17.

FWI at the start 4.6
Minimum humidity 39 %
Days without rain 0
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Sheep Creek Fire, August 2021
3,312 ha 35 days FWI 4.8 Min. humidity 36 % 134 km away, in 2021

First rain (1 mm or more) after it ended: 13.0 mm on 28 Sept.

What happened to them

10 days
median duration
1,566 ha
median area
59 %
went past 1,000 ha
2.7 mm
rain at the end (median; 16 of 17 had it)

It stayed below its twins: 965 ha against a median of 1,566 ha. It lasted 19 days, against 10 days.

In 1 of 17, 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 2.7 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

1.7 mmfirst rain
13 Septthe day after it ended
70km/h · max. gust

It was considered over on 12 Sept, and on 13 Sept 1.7 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 16 of 17, with a median of 2.7 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 · 18 Aug 2022
After · 19 Sept 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 23 August 2022 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
PM1017 µg/m³
Optical depth0.28
23 Aug25 Aug27 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 · 199Every 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 Blodgett Lake Fire last?
The official perimeter only gives the start date (25 August 2022). The end comes from the heat detections inside the perimeter: it burned until 12 September 2022 (19 days from 25 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 965 hectares (9.6 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?
The fire entered 2 counties: Ravalli (946 ha, 0.2 %); Idaho (20 ha, 0.0 %).
What was the weather like?
During the fire the temperature reached 32.0 °C, humidity dropped to 12 % and gusts hit 70 km/h. The fire danger index (FWI) reached 39, 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: 17. Their median duration was 10 days and their median area 1,566 ha; 59 % went past 1,000 ha. In 1 of 17, 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 2.7 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 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.

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.

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. 199 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.