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Buck Fire, August 2020 Valley

Out · last detection 10 Oct 2020, 10:43 UTC

The fire started on 26 August 2020 in Valley, United States, and satellites saw it burning for 46 days. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 7,741 hectares, spread across a single county.

It is the 44th largest in Idaho since 2016 (of 379 with a page). Number 81 in United States in 2020, of 441.

Compare with…

Suggestions: Kiwah · 2018Prospect · 2018Bum Creek · 2018Boundary · 2021

Burnt area
7,741ha
official perimeter (MTBS / NIFC)
Duration
≈ 46days
26 Aug 2020 – 10 Oct 2020
Counties hit
1
counties
Started on
26 Aug
2020
Heat detections
2,454
in a single hotspot: 393 MW
Danger at start
14
Moderate · FWI index
Average daily power
1.3GW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 26 Aug10 Oct
10 Oct 2020

How it evolved, day by day

29 Aug 2020 · 328 MW · 24 30 Aug 2020 · 1,267 MW · 87 1 Sept 2020 · 51 MW · 10 2 Sept 2020 · 342 MW · 23 3 Sept 2020 · 104 MW · 26 4 Sept 2020 · 829 MW · 49 5 Sept 2020 · 8,341 MW · 173 6 Sept 2020 · 1,179 MW · 169 7 Sept 2020 · 109 MW · 59 8 Sept 2020 · 27 MW · 8 9 Sept 2020 · 120 MW · 7 10 Sept 2020 · 1,087 MW · 69 11 Sept 2020 · 994 MW · 83 12 Sept 2020 · 5,422 MW · 117 13 Sept 2020 · 2,686 MW · 167 14 Sept 2020 · 5,412 MW · 331 15 Sept 2020 · 5,955 MW · 458 16 Sept 2020 · 2,281 MW · 269 17 Sept 2020 · 1,739 MW · 165 18 Sept 2020 · 275 MW · 110 20 Sept 2020 · 4 MW · 1 22 Sept 2020 · 6 MW · 6 23 Sept 2020 · 19 MW · 4 24 Sept 2020 · 2 MW · 1 4 Oct 2020 · 7 MW · 2 5 Oct 2020 · 4 MW · 2 6 Oct 2020 · 14 MW · 2 7 Oct 2020 · 26 MW · 5 8 Oct 2020 · 84 MW · 7 9 Oct 2020 · 126 MW · 15 10 Oct 2020 · 9 MW · 5
29 Aug 4 Sept 5 Sept 9 Sept 14 Sept 20 Sept 5 Oct 10 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

30°high
75km/h · peak gust
12%lowest humidity

It had gone 0 days without rain (1 mm or more) when it started. Rain came after the fire: 3.6 mm on 11 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 4.9% of the area of London (77 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. Valley where it started
    7,760 ha reached on 29 Aug
    0.8 %

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)
26 Aug 23.5 °C 29 % 40 km/h 0.2 mm Moderate 14
27 Aug 22.5 °C 27 % 37 km/h 0.7 mm Moderate 17
28 Aug 24.6 °C 18 % 37 km/h 0.0 mm High 26
29 Aug 24.0 °C 18 % 61 km/h 0.0 mm High 33
30 Aug 18.0 °C 20 % 39 km/h 0.0 mm High 28
31 Aug 9.8 °C 46 % 38 km/h 3.9 mm Very low 2
1 Sept 23.1 °C 33 % 42 km/h 0.0 mm Low 8
2 Sept 24.7 °C 21 % 54 km/h 0.0 mm High 23
3 Sept 27.3 °C 18 % 39 km/h 0.0 mm High 27
4 Sept 29.8 °C 12 % 37 km/h 0.0 mm High 34
5 Sept 28.8 °C 14 % 62 km/h 0.0 mm Very high 40
6 Sept 26.9 °C 14 % 43 km/h 0.0 mm High 36
7 Sept 19.8 °C 31 % 71 km/h 1.9 mm Moderate 13
8 Sept 14.4 °C 18 % 65 km/h 0.0 mm High 22
9 Sept 21.8 °C 17 % 27 km/h 0.0 mm High 23
10 Sept 23.5 °C 18 % 31 km/h 0.0 mm High 26
11 Sept 23.8 °C 15 % 36 km/h 0.0 mm High 29
12 Sept 22.1 °C 16 % 41 km/h 0.0 mm High 31
13 Sept 22.1 °C 20 % 46 km/h 0.0 mm High 33
14 Sept 21.2 °C 19 % 47 km/h 0.0 mm High 34
15 Sept 21.8 °C 17 % 47 km/h 0.0 mm High 34
16 Sept 21.5 °C 18 % 39 km/h 0.0 mm High 32
17 Sept 22.5 °C 15 % 40 km/h 0.0 mm High 34
18 Sept 18.0 °C 23 % 52 km/h 3.3 mm Low 7
19 Sept 11.7 °C 72 % 49 km/h 9.9 mm Very low 0
20 Sept 15.8 °C 37 % 45 km/h 0.0 mm Very low 3
21 Sept 21.0 °C 22 % 44 km/h 0.0 mm Low 10
22 Sept 17.5 °C 33 % 57 km/h 0.1 mm Moderate 16
23 Sept 18.2 °C 30 % 54 km/h 0.0 mm Moderate 18
24 Sept 12.4 °C 39 % 61 km/h 0.9 mm Low 11
25 Sept 10.6 °C 51 % 75 km/h 6.5 mm Very low 1
26 Sept 10.8 °C 39 % 67 km/h 11.1 mm Very low 0
27 Sept 12.3 °C 37 % 31 km/h 0.0 mm Very low 1
28 Sept 20.7 °C 26 % 25 km/h 0.0 mm Very low 5
29 Sept 22.0 °C 21 % 32 km/h 0.0 mm Low 11
30 Sept 22.2 °C 17 % 27 km/h 0.0 mm Moderate 15
1 Oct 20.6 °C 19 % 35 km/h 0.0 mm Moderate 16
2 Oct 20.7 °C 22 % 30 km/h 0.0 mm Moderate 16
3 Oct 21.2 °C 21 % 31 km/h 0.0 mm Moderate 17
4 Oct 19.6 °C 24 % 57 km/h 0.0 mm High 22
5 Oct 20.3 °C 25 % 28 km/h 0.0 mm Moderate 18
6 Oct 21.5 °C 25 % 32 km/h 0.0 mm Moderate 19
7 Oct 18.6 °C 24 % 37 km/h 0.0 mm Moderate 20
8 Oct 17.7 °C 19 % 56 km/h 0.0 mm High 24
9 Oct 17.2 °C 26 % 41 km/h 0.0 mm Moderate 20
10 Oct 9.9 °C 30 % 70 km/h 17.4 mm Very low 0
11 Oct after 3.8 °C 65 % 55 km/h 3.6 mm Very low 0

Before and after, from space

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

Before · 19 Aug 2020
After · 17 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 · 2,454Every 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 Buck Fire last?
The official perimeter only gives the start date (26 August 2020). The end comes from the heat detections inside the perimeter: it burned until 10 October 2020 (46 days from 26 August 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 7,741 hectares (77.4 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?
The fire only entered Valley (7,760 ha, 0.8 %).
What was the weather like?
During the fire the temperature reached 29.8 °C, humidity dropped to 12 % and gusts hit 75 km/h. The fire danger index (FWI) reached 40, 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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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. 2,454 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.