How long did the Bear Mountain fire last?

It burned between 9 July 2017 and 9 July 2017: 1 day, according to the start date recorded by United States agencies (MTBS / NIFC) and the heat detections seen by satellite.

How much area did it burn?

The official perimeter published by United States agencies (MTBS / NIFC) is 19,448 hectares (194.5 km²). Other tallies, such as daily incident reports, may give slightly different figures.

Which counties burned?

The fire only entered Yukon-Koyukuk (19,903 ha, 0.0 %).

What was the weather like?

During the fire the temperature reached 26.5 °C, humidity dropped to 28 % and gusts hit 64 km/h. The fire danger index (FWI) reached 20, class Moderate.

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 · 2017-07-09 → 2017-07-09

Bear Mountain Fire, July 2017 Yukon-Koyukuk

Out · last detection 9 Jul 2017, 22:09 UTC

The fire started on 9 July 2017 in Yukon-Koyukuk, United States, and satellites saw it burning for 1 day. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 19,448 hectares, spread across a single county.

It is the 54th largest in Alaska since 2016 (of 472 with a page). Number 41 in United States in 2017, of 619.

Burnt area: 19,448ha; official perimeter (MTBS / NIFC)
Duration: 1day; 9 Jul 2017 – 9 Jul 2017
Municipalities hit: 1; counties
Started on: 9 Jul; 2017
Heat detections: 1,137; in a single hotspot: 686 MW
Danger at start: 6; Low · FWI index
Energy released: 3.4GW; sum of detected power

HOTSPOTS BY DAY 9 Jul9 Jul

How it evolved, day by day

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

The weather it burned in

26°high

64km/h · peak gust

28%lowest humidity

It had gone 6 days without rain (1 mm or more) when it started. Rain came after the fire: 8.1 mm on 14 Aug.

This area had burned before

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

What happened to each town

Yukon-Koyukuk where it started

19,903 ha reached on 9 Jul

0.0 %

Burnt area inside each county, from crossing the official perimeter with administrative boundaries. The distance is from the town centre to the nearest fire: staying a kilometre away does not mean it reached the houses.

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)
9 Jul	23.7 °C	28 %	30 km/h	2.8 mm	Low 6
10 Jul after	21.4 °C	65 %	37 km/h	9.3 mm	Very low 0
11 Jul after	23.8 °C	44 %	49 km/h	0.1 mm	Very low 5
12 Jul after	22.2 °C	44 %	32 km/h	0.0 mm	Low 9
13 Jul after	24.3 °C	32 %	24 km/h	0.0 mm	Moderate 13
14 Jul after	26.4 °C	28 %	16 km/h	0.0 mm	Moderate 16
15 Jul after	24.9 °C	34 %	33 km/h	0.1 mm	Moderate 20
16 Jul after	20.6 °C	68 %	33 km/h	18.0 mm	Very low 0
17 Jul after	23.4 °C	44 %	37 km/h	2.0 mm	Very low 1
18 Jul after	23.7 °C	47 %	16 km/h	0.8 mm	Very low 3
19 Jul after	26.5 °C	39 %	18 km/h	0.3 mm	Low 8
20 Jul after	23.1 °C	41 %	36 km/h	5.0 mm	Very low 2
21 Jul after	16.4 °C	49 %	40 km/h	6.1 mm	Very low 0
22 Jul after	23.2 °C	35 %	44 km/h	0.0 mm	Very low 5
23 Jul after	24.9 °C	37 %	62 km/h	0.0 mm	Moderate 13
24 Jul after	19.6 °C	56 %	64 km/h	5.8 mm	Very low 1
25 Jul after	18.9 °C	49 %	28 km/h	0.4 mm	Very low 2
26 Jul after	17.5 °C	63 %	37 km/h	0.2 mm	Very low 4
27 Jul after	19.4 °C	49 %	28 km/h	0.0 mm	Low 5
28 Jul after	21.0 °C	41 %	20 km/h	0.0 mm	Low 7
29 Jul after	23.1 °C	33 %	16 km/h	0.0 mm	Low 9
30 Jul after	24.3 °C	32 %	18 km/h	0.0 mm	Moderate 11
31 Jul after	23.2 °C	45 %	35 km/h	2.3 mm	Very low 3
1 Aug after	20.4 °C	40 %	39 km/h	0.0 mm	Low 8
2 Aug after	18.4 °C	47 %	31 km/h	1.1 mm	Very low 5
3 Aug after	20.8 °C	48 %	28 km/h	0.0 mm	Low 8
4 Aug after	17.6 °C	70 %	28 km/h	3.7 mm	Very low 1
5 Aug after	22.2 °C	46 %	18 km/h	0.3 mm	Very low 2
6 Aug after	25.7 °C	39 %	14 km/h	0.0 mm	Low 7
7 Aug after	26.3 °C	41 %	35 km/h	1.4 mm	Low 7
8 Aug after	23.7 °C	41 %	46 km/h	0.8 mm	Moderate 12
9 Aug after	25.5 °C	31 %	14 km/h	0.0 mm	Moderate 13
10 Aug after	25.7 °C	34 %	41 km/h	0.5 mm	Moderate 18
11 Aug after	19.8 °C	44 %	17 km/h	0.0 mm	Moderate 14
12 Aug after	19.3 °C	58 %	23 km/h	2.4 mm	Very low 2
13 Aug after	22.2 °C	48 %	37 km/h	5.4 mm	Very low 1
14 Aug after	13.6 °C	77 %	27 km/h	8.1 mm	Very low 0

Before and after, from space

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

↔

Before · 2 Jul 2017

After · 16 Jul 2017

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 · 1,137Every 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 Bear Mountain fire last?: It burned between 9 July 2017 and 9 July 2017: 1 day, according to the start date recorded by United States agencies (MTBS / NIFC) and the heat detections seen by satellite.
How much area did it burn?: The official perimeter published by United States agencies (MTBS / NIFC) is 19,448 hectares (194.5 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?: The fire only entered Yukon-Koyukuk (19,903 ha, 0.0 %).
What was the weather like?: During the fire the temperature reached 26.5 °C, humidity dropped to 28 % and gusts hit 64 km/h. The fire danger index (FWI) reached 20, class Moderate.
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

Satellite cross-check

NASA FIRMS ↗
NIFC · Fire maps ↗

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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