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Mcclusky Fire, August 2019 Jefferson

Out · last detection 5 Sept 2019, 20:48 UTC

The fire started on 16 August 2019 in Jefferson, United States, and satellites saw it burning for 21 days. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 1,094 hectares, spread across a single county.

It is the 172th largest in Montana since 2016 (of 302 with a page). Number 193 in United States in 2019, of 367.

Compare with…
Burnt area
1,094ha
official perimeter (MTBS / NIFC)
Duration
≈ 21days
16 Aug 2019 – 5 Sept 2019
Counties hit
1
counties
Started on
16 Aug
2019
Heat detections
250
in a single hotspot: 136 MW
Danger at start
11
Low · FWI index
Average daily power
250MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 16 Aug5 Sept
5 Sept 2019

How it evolved, day by day

18 Aug 2019 · 20 MW · 3 19 Aug 2019 · 56 MW · 11 20 Aug 2019 · 98 MW · 8 21 Aug 2019 · 101 MW · 7 22 Aug 2019 · 4 MW · 2 27 Aug 2019 · 2 MW · 1 28 Aug 2019 · 36 MW · 5 29 Aug 2019 · 24 MW · 7 30 Aug 2019 · 4 MW · 4 31 Aug 2019 · 64 MW · 9 1 Sept 2019 · 3 MW · 3 2 Sept 2019 · 278 MW · 20 3 Sept 2019 · 112 MW · 19 4 Sept 2019 · 2,105 MW · 46 5 Sept 2019 · 845 MW · 105
18 Aug 21 Aug 28 Aug 31 Aug 3 Sept 4 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

29°high
68km/h · peak gust
10%lowest humidity

It had gone 0 days without rain (1 mm or more) when it started. Rain came after the fire: 7.7 mm on 6 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 0.7% of the area of London (11 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. Jefferson where it started
    1,096 ha reached on 18 Aug
    0.3 %

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)

Day High Min. humidity Peak gust Rain Danger (FWI)
16 Aug 20.4 °C 27 % 43 km/h 0.0 mm Low 11
17 Aug 16.7 °C 34 % 46 km/h 0.2 mm Moderate 13
18 Aug 24.9 °C 20 % 36 km/h 0.0 mm Moderate 18
19 Aug 27.7 °C 17 % 41 km/h 0.0 mm High 22
20 Aug 26.0 °C 22 % 26 km/h 0.4 mm Moderate 21
21 Aug 27.3 °C 19 % 26 km/h 0.1 mm High 22
22 Aug 18.6 °C 36 % 31 km/h 4.6 mm Very low 2
23 Aug 19.0 °C 39 % 20 km/h 0.2 mm Very low 4
24 Aug 23.9 °C 23 % 49 km/h 0.0 mm Moderate 17
25 Aug 19.6 °C 27 % 68 km/h 0.3 mm High 23
26 Aug 20.0 °C 18 % 50 km/h 0.0 mm High 23
27 Aug 22.3 °C 20 % 25 km/h 0.0 mm Moderate 20
28 Aug 27.0 °C 11 % 40 km/h 0.0 mm High 30
29 Aug 19.4 °C 36 % 33 km/h 0.7 mm Moderate 15
30 Aug 22.6 °C 32 % 41 km/h 0.0 mm Moderate 19
31 Aug 26.0 °C 20 % 28 km/h 0.0 mm High 22
1 Sept 28.1 °C 12 % 26 km/h 0.0 mm High 30
2 Sept 27.2 °C 15 % 51 km/h 0.1 mm High 36
3 Sept 27.1 °C 17 % 23 km/h 0.0 mm High 28
4 Sept 28.8 °C 10 % 55 km/h 0.0 mm Very high 42
5 Sept 27.8 °C 14 % 23 km/h 0.0 mm High 35
6 Sept after 19.4 °C 36 % 34 km/h 7.7 mm Very low 2

Before and after, from space

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

Before · 9 Aug 2019
After · 12 Sept 2019

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 · 250Every 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 Mcclusky Fire last?
The official perimeter only gives the start date (16 August 2019). The end comes from the heat detections inside the perimeter: it burned until 5 September 2019 (21 days from 16 August 2019), 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 1,094 hectares (10.9 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?
The fire only entered Jefferson (1,096 ha, 0.3 %).
What was the weather like?
During the fire the temperature reached 28.8 °C, humidity dropped to 10 % and gusts hit 68 km/h. The fire danger index (FWI) reached 42, 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

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.

RSS Changes to this page

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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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. 250 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.