How long did the Badger Fire last?

The official perimeter only gives the start date (12 September 2020). The end comes from the heat detections inside the perimeter: it burned until 8 October 2020 (27 days from 12 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 35,166 hectares (351.7 km²). Other tallies, such as daily incident reports, may give slightly different figures.

Which counties burned?

The fire entered 2 counties: Cassia (33,675 ha, 5.0 %); Twin Falls (1,427 ha, 0.3 %).

What was the weather like?

During the fire the temperature reached 28.5 °C, humidity dropped to 5 % and gusts hit 58 km/h. The fire danger index (FWI) reached 58, 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.

US · United States · 2020-09-12 → 2020-10-08

Badger Fire, September 2020 Cassia, Twin Falls

Out · last detection 8 Oct 2020, 09:42 UTC

The fire started on 12 September 2020 in Cassia, United States, and satellites saw it burning for 27 days. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 35,166 hectares, spread across 2 counties.

It is the 13th largest in Idaho since 2016 (of 379 with a page). Number 27 in United States in 2020, of 441.

Compare with…

Suggestions: Black Mountain · 2023 Piney · 2017 Goose · 2019 Summit Creek · 2026

Burnt area: 35,166ha; official perimeter (MTBS / NIFC)
Duration: ≈ 27days; 12 Sept 2020 – 8 Oct 2020
Counties hit: 2; counties
Started on: 12 Sept; 2020
Heat detections: 1,576; in a single hotspot: 883 MW
Danger at start: 39; Very high · FWI index
Average daily power: 2.9GW; detected power per day, on average

HOTSPOTS BY DAY 12 Sept8 Oct

Play back 8 Oct 2020

How it evolved, day by day

13 Sept 14 Sept 16 Sept 19 Sept 22 Sept 25 Sept 1 Oct 8 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

28°high

58km/h · peak gust

5%lowest humidity

It had gone 4 days without rain (1 mm or more) when it started. Rain came after the fire: 3.2 mm on 10 Oct.

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 22% of the area of London (352 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

Cassia where it started

33,675 ha reached on 13 Sept

5.0 %
Twin Falls

1,427 ha reached on 19 Sept

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 2020

Built-up area0.21 ha

Residents< 20

Inside the perimeter there were about 0.21 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)
12 Sept	24.3 °C	10 %	32 km/h	0.0 mm	Very high 39
13 Sept	27.3 °C	8 %	27 km/h	0.0 mm	Very high 40
14 Sept	28.5 °C	5 %	39 km/h	0.0 mm	Very high 47
15 Sept	26.1 °C	8 %	28 km/h	0.0 mm	Very high 45
16 Sept	26.2 °C	11 %	29 km/h	0.0 mm	Very high 46
17 Sept	27.1 °C	9 %	42 km/h	0.0 mm	Extreme 52
18 Sept	20.6 °C	15 %	58 km/h	0.1 mm	Extreme 58
19 Sept	16.5 °C	34 %	44 km/h	1.9 mm	Moderate 12
20 Sept	19.5 °C	21 %	25 km/h	0.0 mm	Moderate 20
21 Sept	24.7 °C	17 %	27 km/h	0.0 mm	High 29
22 Sept	23.5 °C	10 %	37 km/h	0.0 mm	Very high 42
23 Sept	24.4 °C	12 %	31 km/h	0.0 mm	Very high 38
24 Sept	22.9 °C	15 %	44 km/h	0.0 mm	Very high 47
25 Sept	21.3 °C	13 %	53 km/h	0.0 mm	Very high 50
26 Sept	13.4 °C	36 %	46 km/h	0.1 mm	High 35
27 Sept	12.5 °C	29 %	44 km/h	0.0 mm	High 33
28 Sept	17.6 °C	16 %	21 km/h	0.0 mm	High 29
29 Sept	22.4 °C	13 %	18 km/h	0.0 mm	High 32
30 Sept	22.0 °C	10 %	32 km/h	0.0 mm	Very high 40
1 Oct	23.5 °C	10 %	22 km/h	0.0 mm	High 38
2 Oct	20.6 °C	14 %	36 km/h	0.0 mm	Very high 43
3 Oct	21.1 °C	13 %	26 km/h	0.0 mm	Very high 40
4 Oct	24.0 °C	8 %	24 km/h	0.0 mm	Very high 41
5 Oct	20.4 °C	13 %	33 km/h	0.0 mm	Very high 43
6 Oct	22.5 °C	11 %	22 km/h	0.0 mm	Very high 38
7 Oct	23.1 °C	12 %	25 km/h	0.0 mm	Very high 41
8 Oct	22.1 °C	8 %	29 km/h	0.0 mm	Very high 42
9 Oct after	21.6 °C	4 %	20 km/h	0.0 mm	Very high 40
10 Oct after	19.1 °C	11 %	58 km/h	3.2 mm	Moderate 18

Before and after, from space

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

↔

Before · 5 Sept 2020

After · 15 Oct 2020

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 · 1,576Every 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 Badger Fire last?: The official perimeter only gives the start date (12 September 2020). The end comes from the heat detections inside the perimeter: it burned until 8 October 2020 (27 days from 12 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 35,166 hectares (351.7 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?: The fire entered 2 counties: Cassia (33,675 ha, 5.0 %); Twin Falls (1,427 ha, 0.3 %).
What was the weather like?: During the fire the temperature reached 28.5 °C, humidity dropped to 5 % and gusts hit 58 km/h. The fire danger index (FWI) reached 58, 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

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.

RSS Changes to this page

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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. 1,576 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