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Gibralter Ridge Fire, August 2017 Lincoln

Out · last detection 17 Sept 2017, 20:11 UTC

The fire started on 8 August 2017 in Lincoln, United States, and satellites saw it burning for 41 days. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 2,548 hectares, spread across a single county.

It is the 91th largest in Montana since 2016 (of 302 with a page). Number 229 in United States in 2017, of 619.

Burnt area
2,548ha
official perimeter (MTBS / NIFC)
Duration
≈ 41days
8 Aug 2017 – 17 Sept 2017
Counties hit
1
counties
Started on
8 Aug
2017
Heat detections
559
in a single hotspot: 261 MW
Danger at start
22
High · FWI index
Average daily power
168MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 8 Aug17 Sept
17 Sept 2017

How it evolved, day by day

8 Aug 2017 · 1,033 MW · 73 9 Aug 2017 · 211 MW · 38 10 Aug 2017 · 178 MW · 46 11 Aug 2017 · 38 MW · 16 12 Aug 2017 · 107 MW · 29 13 Aug 2017 · 20 MW · 5 15 Aug 2017 · 3 MW · 1 16 Aug 2017 · 1 MW · 1 17 Aug 2017 · 281 MW · 27 18 Aug 2017 · 185 MW · 32 19 Aug 2017 · 23 MW · 18 20 Aug 2017 · 97 MW · 13 21 Aug 2017 · 8 MW · 7 22 Aug 2017 · 47 MW · 5 23 Aug 2017 · 2,490 MW · 42 25 Aug 2017 · 28 MW · 11 26 Aug 2017 · 124 MW · 23 27 Aug 2017 · 37 MW · 18 28 Aug 2017 · 393 MW · 35 29 Aug 2017 · 89 MW · 33 30 Aug 2017 · 248 MW · 24 31 Aug 2017 · 4 MW · 4 2 Sept 2017 · 0 MW · 1 3 Sept 2017 · 1 MW · 1 4 Sept 2017 · 33 MW · 3 5 Sept 2017 · 5 MW · 2 6 Sept 2017 · 13 MW · 7 7 Sept 2017 · 5 MW · 2 8 Sept 2017 · 17 MW · 7 9 Sept 2017 · 20 MW · 8 10 Sept 2017 · 20 MW · 5 11 Sept 2017 · 82 MW · 12 12 Sept 2017 · 23 MW · 7 16 Sept 2017 · 2 MW · 1 17 Sept 2017 · 5 MW · 2
8 Aug 16 Aug 23 Aug 31 Aug 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

28°high
68km/h · peak gust
10%lowest humidity

It had gone 3 days without rain (1 mm or more) when it started. Rain came after the fire: 10.6 mm on 18 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 1.6% of the area of London (25 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. Lincoln where it started
    2,563 ha reached on 8 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 2015
Built-up area< 0.1 ha
Residents< 20

Inside the perimeter there was no noticeable built-up land and almost nobody lived there (GHSL 2015, 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)
8 Aug 23.6 °C 26 % 34 km/h 0.9 mm High 22
9 Aug 24.7 °C 23 % 22 km/h 1.3 mm Moderate 18
10 Aug 24.9 °C 21 % 26 km/h 0.7 mm Moderate 18
11 Aug 25.8 °C 17 % 29 km/h 0.0 mm Moderate 20
12 Aug 26.2 °C 15 % 32 km/h 0.0 mm High 29
13 Aug 15.7 °C 47 % 53 km/h 1.9 mm Moderate 13
14 Aug 15.3 °C 37 % 47 km/h 0.7 mm Low 10
15 Aug 19.8 °C 21 % 40 km/h 0.0 mm High 22
16 Aug 21.6 °C 22 % 48 km/h 0.0 mm High 32
17 Aug 22.8 °C 19 % 46 km/h 0.0 mm High 36
18 Aug 23.1 °C 18 % 55 km/h 0.0 mm Very high 42
19 Aug 18.8 °C 19 % 50 km/h 0.0 mm Very high 42
20 Aug 18.5 °C 21 % 44 km/h 0.0 mm Very high 39
21 Aug 20.7 °C 20 % 27 km/h 0.0 mm High 29
22 Aug 25.4 °C 17 % 26 km/h 0.0 mm High 32
23 Aug 25.5 °C 16 % 43 km/h 0.0 mm Very high 41
24 Aug 19.3 °C 27 % 60 km/h 1.3 mm Moderate 18
25 Aug 19.6 °C 11 % 40 km/h 0.0 mm High 34
26 Aug 22.3 °C 15 % 34 km/h 0.0 mm High 36
27 Aug 26.2 °C 11 % 30 km/h 0.0 mm Very high 39
28 Aug 26.9 °C 11 % 28 km/h 0.0 mm High 38
29 Aug 27.7 °C 13 % 36 km/h 0.2 mm Very high 44
30 Aug 26.2 °C 16 % 44 km/h 0.2 mm Very high 40
31 Aug 21.8 °C 19 % 55 km/h 0.0 mm Extreme 54
1 Sept 23.0 °C 18 % 54 km/h 0.0 mm Very high 50
2 Sept 26.5 °C 14 % 53 km/h 0.0 mm Very high 46
3 Sept 27.0 °C 10 % 48 km/h 0.0 mm Very high 47
4 Sept 20.8 °C 24 % 37 km/h 0.0 mm Very high 40
5 Sept 22.2 °C 16 % 19 km/h 0.0 mm High 31
6 Sept 24.8 °C 15 % 21 km/h 0.0 mm High 32
7 Sept 26.3 °C 16 % 26 km/h 0.0 mm Very high 38
8 Sept 22.7 °C 26 % 46 km/h 0.0 mm Very high 40
9 Sept 21.9 °C 29 % 68 km/h 1.6 mm High 36
10 Sept 17.4 °C 24 % 52 km/h 0.0 mm High 28
11 Sept 21.9 °C 14 % 48 km/h 0.0 mm High 32
12 Sept 21.1 °C 18 % 49 km/h 0.0 mm Very high 38
13 Sept 15.5 °C 21 % 48 km/h 0.0 mm Very high 41
14 Sept 6.2 °C 50 % 46 km/h 0.0 mm High 28
15 Sept 6.9 °C 27 % 41 km/h 0.3 mm High 26
16 Sept 10.8 °C 23 % 35 km/h 0.0 mm High 24
17 Sept 13.4 °C 20 % 42 km/h 0.0 mm High 29
18 Sept after 7.5 °C 49 % 43 km/h 10.6 mm Very low 0

Its twins: fires that started in the same weather

It started with an FWI of 21.6, a minimum humidity of 26% and 3 days without rain. Fires in the area that started in weather like this since 2016: 31.

FWI at the start 21.6
Minimum humidity 26 %
Days without rain 3
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Government Fire, September 2022
1,167 ha 21 days FWI 25.7 Min. humidity 26 % 114 km away, in 2022

First rain (1 mm or more) after it ended: 15.3 mm on 22 Sept.

What happened to them

21 days
median duration
2,607 ha
median area
81 %
went past 1,000 ha
4.3 mm
rain at the end (median; 30 of 31 had it)

It burned an area similar to its twins (2,548 ha against a median of 2,607 ha) and lasted 41 days, against 21 days.

In 1 of 31, 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 4.3 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

10.6 mmfirst rain
18 Septthe day after it ended
68km/h · max. gust

It was considered over on 17 Sept, and on 18 Sept 10.6 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 30 of 31, with a median of 4.3 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 · 1 Aug 2017
After · 24 Sept 2017

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 · 559Every 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 Gibralter Ridge Fire last?
The official perimeter only gives the start date (8 August 2017). The end comes from the heat detections inside the perimeter: it burned until 17 September 2017 (41 days from 8 August 2017), 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 2,548 hectares (25.5 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?
The fire only entered Lincoln (2,563 ha, 0.3 %).
What was the weather like?
During the fire the temperature reached 27.7 °C, humidity dropped to 10 % and gusts hit 68 km/h. The fire danger index (FWI) reached 54, class Extreme.
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: 31. Their median duration was 21 days and their median area 2,607 ha; 81 % went past 1,000 ha. In 1 of 31, 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 4.3 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. 559 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 2015, 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.