Skip to content
worldfires
en
US · United States · →

Middle Fork Fire, September 2020 Routt, Jackson

Out · last detection 24 Oct 2020, 09:42 UTC

The fire started on 6 September 2020 in Routt, United States, and satellites saw it burning for 49 days. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 8,449 hectares, spread across 2 counties.

It is the 17th largest in Colorado since 2016 (of 167 with a page). Number 78 in United States in 2020, of 441.

Compare with…

Suggestions: Morgan Creek · 2021Big Red · 2017Beaver Creek · 2016

Burnt area
8,449ha
official perimeter (MTBS / NIFC)
Duration
≈ 49days
6 Sept 2020 – 24 Oct 2020
Counties hit
2
counties
Started on
6 Sept
2020
Heat detections
2,262
in a single hotspot: 588 MW
Danger at start
51
Extreme · FWI index
Average daily power
1.3GW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 6 Sept24 Oct
24 Oct 2020

How it evolved, day by day

7 Sept 2020 · 5,333 MW · 59 9 Sept 2020 · 1 MW · 1 12 Sept 2020 · 5 MW · 1 13 Sept 2020 · 345 MW · 17 14 Sept 2020 · 341 MW · 37 15 Sept 2020 · 303 MW · 47 16 Sept 2020 · 1,343 MW · 73 17 Sept 2020 · 1,186 MW · 97 18 Sept 2020 · 534 MW · 71 19 Sept 2020 · 36 MW · 25 20 Sept 2020 · 38 MW · 11 21 Sept 2020 · 240 MW · 23 22 Sept 2020 · 136 MW · 34 23 Sept 2020 · 37 MW · 14 24 Sept 2020 · 576 MW · 42 25 Sept 2020 · 872 MW · 95 26 Sept 2020 · 298 MW · 81 27 Sept 2020 · 35 MW · 5 28 Sept 2020 · 84 MW · 18 29 Sept 2020 · 321 MW · 26 30 Sept 2020 · 377 MW · 46 1 Oct 2020 · 404 MW · 65 2 Oct 2020 · 61 MW · 19 3 Oct 2020 · 227 MW · 35 4 Oct 2020 · 800 MW · 49 5 Oct 2020 · 1,734 MW · 82 6 Oct 2020 · 3,058 MW · 96 7 Oct 2020 · 1,999 MW · 144 8 Oct 2020 · 24,595 MW · 337 9 Oct 2020 · 5,296 MW · 300 10 Oct 2020 · 1,824 MW · 163 12 Oct 2020 · 15 MW · 7 13 Oct 2020 · 12 MW · 7 14 Oct 2020 · 19 MW · 12 15 Oct 2020 · 8 MW · 2 16 Oct 2020 · 24 MW · 4 17 Oct 2020 · 93 MW · 15 19 Oct 2020 · 22 MW · 4 20 Oct 2020 · 34 MW · 12 21 Oct 2020 · 1,135 MW · 37 22 Oct 2020 · 206 MW · 33 23 Oct 2020 · 10 MW · 2 24 Oct 2020 · 45 MW · 14
7 Sept 17 Sept 24 Sept 1 Oct 8 Oct 16 Oct 24 Oct

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

The weather it burned in

24°high
94km/h · peak gust
10%lowest humidity

It had gone 7 days without rain (1 mm or more) when it started. Rain came after the fire: 13.5 mm on 25 Oct.

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 5.3% of the area of London (84 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. Routt where it started
    8,461 ha reached on 7 Sept
    1.4 %
  2. Jackson
    11 ha
    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 area0.14 ha
Residents< 20

Inside the perimeter there were about 0.14 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)
6 Sept 24.4 °C 12 % 57 km/h 0.0 mm Extreme 51
7 Sept 19.4 °C 12 % 64 km/h 0.0 mm Extreme 51
8 Sept 5.7 °C 60 % 94 km/h 13.2 mm Very low 0
9 Sept 3.0 °C 55 % 36 km/h 0.6 mm Very low 2
10 Sept 4.5 °C 62 % 33 km/h 3.4 mm Very low 0
11 Sept 7.9 °C 43 % 60 km/h 0.5 mm Very low 5
12 Sept 17.0 °C 22 % 33 km/h 0.0 mm Low 8
13 Sept 19.6 °C 12 % 26 km/h 0.0 mm Moderate 19
14 Sept 20.1 °C 13 % 41 km/h 0.0 mm High 27
15 Sept 20.2 °C 11 % 33 km/h 0.0 mm High 29
16 Sept 19.1 °C 16 % 25 km/h 0.0 mm High 26
17 Sept 19.9 °C 14 % 31 km/h 0.0 mm High 28
18 Sept 18.2 °C 16 % 38 km/h 0.0 mm High 31
19 Sept 17.6 °C 19 % 64 km/h 0.3 mm Very high 39
20 Sept 15.9 °C 26 % 63 km/h 0.0 mm High 34
21 Sept 18.6 °C 19 % 46 km/h 0.0 mm High 29
22 Sept 18.3 °C 19 % 43 km/h 0.2 mm High 30
23 Sept 17.6 °C 20 % 48 km/h 0.0 mm High 32
24 Sept 19.9 °C 17 % 51 km/h 0.0 mm High 33
25 Sept 18.6 °C 16 % 67 km/h 0.0 mm Very high 38
26 Sept 14.9 °C 23 % 74 km/h 0.4 mm Very high 39
27 Sept 6.3 °C 38 % 59 km/h 0.7 mm Moderate 21
28 Sept 7.8 °C 17 % 39 km/h 0.0 mm Moderate 21
29 Sept 15.7 °C 15 % 45 km/h 0.0 mm High 29
30 Sept 16.2 °C 15 % 38 km/h 0.0 mm High 29
1 Oct 14.7 °C 18 % 35 km/h 0.0 mm High 28
2 Oct 13.7 °C 18 % 50 km/h 0.0 mm High 33
3 Oct 13.7 °C 21 % 37 km/h 0.0 mm High 29
4 Oct 16.2 °C 21 % 53 km/h 0.0 mm High 34
5 Oct 15.9 °C 14 % 54 km/h 0.0 mm High 36
6 Oct 17.7 °C 12 % 46 km/h 0.0 mm High 36
7 Oct 18.2 °C 10 % 35 km/h 0.0 mm High 34
8 Oct 17.4 °C 11 % 48 km/h 0.0 mm Very high 40
9 Oct 16.5 °C 16 % 44 km/h 0.0 mm High 37
10 Oct 16.0 °C 19 % 57 km/h 0.0 mm Very high 40
11 Oct 7.4 °C 32 % 69 km/h 5.8 mm Very low 4
12 Oct 9.3 °C 21 % 73 km/h 0.0 mm Low 11
13 Oct 12.1 °C 22 % 65 km/h 0.0 mm Moderate 20
14 Oct 8.5 °C 23 % 88 km/h 0.7 mm High 24
15 Oct 2.4 °C 28 % 62 km/h 0.0 mm Moderate 21
16 Oct 7.4 °C 25 % 65 km/h 0.0 mm High 23
17 Oct 7.3 °C 36 % 75 km/h 0.0 mm High 25
18 Oct 7.2 °C 42 % 79 km/h 0.6 mm Moderate 21
19 Oct 8.6 °C 31 % 63 km/h 0.0 mm Moderate 21
20 Oct 7.9 °C 34 % 69 km/h 0.0 mm High 22
21 Oct 12.3 °C 20 % 71 km/h 0.0 mm High 29
22 Oct 4.8 °C 31 % 52 km/h 0.0 mm High 22
23 Oct -1.1 °C 34 % 40 km/h 0.0 mm Moderate 18
24 Oct 1.4 °C 41 % 63 km/h 1.0 mm Moderate 11
25 Oct after -3.4 °C 75 % 35 km/h 13.5 mm Very low 0

Before and after, from space

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

Before · 30 Aug 2020
After · 31 Oct 2020

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 · 2,262Every 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 Middle Fork Fire last?
The official perimeter only gives the start date (6 September 2020). The end comes from the heat detections inside the perimeter: it burned until 24 October 2020 (49 days from 6 September 2020), 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 8,449 hectares (84.5 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?
The fire entered 2 counties: Routt (8,461 ha, 1.4 %); Jackson (11 ha, 0.0 %).
What was the weather like?
During the fire the temperature reached 24.4 °C, humidity dropped to 10 % and gusts hit 94 km/h. The fire danger index (FWI) reached 51, 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.

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.

Report an error
What do you think is wrong?

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. 2,262 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.