How long did the Howe Ridge Fire last?

The official perimeter only gives the start date (11 August 2018). The end comes from the heat detections inside the perimeter: it burned until 12 September 2018 (33 days from 11 August 2018), 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 5,970 hectares (59.7 km²). Other tallies, such as daily incident reports, may give slightly different figures.

Which counties burned?

The fire only entered Flathead (6,000 ha, 0.4 %).

What was the weather like?

During the fire the temperature reached 29.3 °C, humidity dropped to 14 % and gusts hit 76 km/h. The fire danger index (FWI) reached 37, class 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 · 2018-08-11 → 2018-09-12

Howe Ridge Fire, August 2018 Flathead

Out · last detection 12 Sept 2018, 19:21 UTC

The fire started on 11 August 2018 in Flathead, United States, and satellites saw it burning for 33 days. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 5,970 hectares, spread across a single county.

It is the 50th largest in Montana since 2016 (of 302 with a page). Number 94 in United States in 2018, of 511.

Compare with…

Suggestions: Sprague · 2017 Adair Peak · 2017 Quartz · 2022 Ridge · 2023

Burnt area: 5,970ha; official perimeter (MTBS / NIFC)
Duration: ≈ 33days; 11 Aug 2018 – 12 Sept 2018
Counties hit: 1; counties
Started on: 11 Aug; 2018
Heat detections: 1,796; in a single hotspot: 572 MW
Danger at start: 37; High · FWI index
Average daily power: 861MW; detected power per day, on average

HOTSPOTS BY DAY 11 Aug12 Sept

Play back 12 Sept 2018

How it evolved, day by day

12 Aug 16 Aug 20 Aug 24 Aug 31 Aug 4 Sept 8 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

76km/h · peak gust

14%lowest humidity

It had gone 5 days without rain (1 mm or more) when it started. Rain came after the fire: 2.8 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?

It burned the equivalent of 3.8% of the area of London (60 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

Flathead where it started

6,000 ha reached on 12 Aug

0.4 %

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 area0.25 ha

Residents< 20

Inside the perimeter there were about 0.25 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)
11 Aug	29.3 °C	15 %	58 km/h	0.6 mm	High 37
12 Aug	20.1 °C	32 %	62 km/h	0.0 mm	High 31
13 Aug	22.4 °C	23 %	25 km/h	0.0 mm	High 24
14 Aug	25.1 °C	18 %	38 km/h	0.0 mm	High 29
15 Aug	26.4 °C	19 %	41 km/h	0.0 mm	High 31
16 Aug	26.2 °C	14 %	42 km/h	0.0 mm	High 34
17 Aug	26.5 °C	26 %	49 km/h	0.6 mm	High 30
18 Aug	23.1 °C	19 %	32 km/h	0.0 mm	High 29
19 Aug	21.4 °C	29 %	38 km/h	0.1 mm	High 28
20 Aug	16.1 °C	42 %	64 km/h	0.0 mm	High 28
21 Aug	24.1 °C	18 %	28 km/h	0.0 mm	High 26
22 Aug	24.3 °C	19 %	44 km/h	0.0 mm	High 32
23 Aug	23.0 °C	24 %	54 km/h	0.0 mm	High 35
24 Aug	16.3 °C	34 %	68 km/h	0.2 mm	High 33
25 Aug	17.1 °C	31 %	45 km/h	0.0 mm	High 28
26 Aug	13.3 °C	52 %	55 km/h	2.4 mm	Low 6
27 Aug	9.2 °C	60 %	56 km/h	12.5 mm	Very low 0
28 Aug	15.2 °C	45 %	50 km/h	0.0 mm	Very low 4
29 Aug	20.7 °C	29 %	70 km/h	0.0 mm	Moderate 12
30 Aug	18.6 °C	26 %	62 km/h	0.0 mm	Moderate 20
31 Aug	17.9 °C	30 %	63 km/h	0.0 mm	High 22
1 Sept	16.2 °C	34 %	53 km/h	0.2 mm	Moderate 21
2 Sept	18.9 °C	28 %	57 km/h	0.0 mm	High 22
3 Sept	17.0 °C	35 %	64 km/h	0.4 mm	High 24
4 Sept	16.6 °C	33 %	30 km/h	0.0 mm	Moderate 19
5 Sept	22.5 °C	20 %	32 km/h	0.0 mm	High 23
6 Sept	26.9 °C	14 %	47 km/h	0.0 mm	High 34
7 Sept	24.8 °C	15 %	53 km/h	0.0 mm	High 34
8 Sept	19.7 °C	29 %	63 km/h	0.0 mm	High 32
9 Sept	18.0 °C	30 %	49 km/h	0.0 mm	High 27
10 Sept	17.0 °C	32 %	76 km/h	1.8 mm	Moderate 13
11 Sept	12.6 °C	50 %	38 km/h	0.7 mm	Low 9
12 Sept	11.8 °C	51 %	46 km/h	0.8 mm	Low 8
13 Sept after	9.1 °C	64 %	53 km/h	2.8 mm	Very low 2

Before and after, from space

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

↔

Before · 4 Aug 2018

After · 19 Sept 2018

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 · 1,796Every 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 Howe Ridge Fire last?: The official perimeter only gives the start date (11 August 2018). The end comes from the heat detections inside the perimeter: it burned until 12 September 2018 (33 days from 11 August 2018), 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 5,970 hectares (59.7 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?: The fire only entered Flathead (6,000 ha, 0.4 %).
What was the weather like?: During the fire the temperature reached 29.3 °C, humidity dropped to 14 % and gusts hit 76 km/h. The fire danger index (FWI) reached 37, class 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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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. 1,796 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