Skip to content
worldfires
US · United States · →

Doublesprings Fire, July 2026 Custer

Out · last detection 31 Jul 2026, 10:06 UTC

The fire started on 24 July 2026 in Custer, United States, and satellites saw it burning for 8 days. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 687 hectares, spread across a single county.

It is the 286th largest in Idaho since 2016 (of 379 with a page). Number 320 in United States in 2026, of 423.

The power measured by the satellite is low (18.8 MW in the strongest hotspot), more typical of grass or stubble burning, or a slow surface fire, than of a large crown fire.

Compare with…

Suggestions: Mill · 2025

Burnt area
687ha
official perimeter (MTBS / NIFC)
Duration
≈ 8days
24 Jul 2026 – 31 Jul 2026
Counties hit
1
counties
Started on
24 Jul
2026
Heat detections
15
in a single hotspot: 19 MW
Danger at start
9
Low · FWI index
Average daily power
14MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 24 Jul31 Jul
31 Jul 2026

How it evolved, day by day

26 Jul 2026 · 11 MW · 2 27 Jul 2026 · 43 MW · 5 28 Jul 2026 · 20 MW · 3 29 Jul 2026 · 4 MW · 1 30 Jul 2026 · 8 MW · 3 31 Jul 2026 · 2 MW · 1
26 Jul 27 Jul 28 Jul 29 Jul 30 Jul 31 Jul

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
51km/h · peak gust
15%lowest humidity

It had gone one day without rain (1 mm or more) when it started.

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 0.4% of the area of London (6.9 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. Custer where it started
    687 ha reached on 26 Jul
    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 2025
Built-up area< 0.1 ha
Residents< 20

Inside the perimeter there was no noticeable built-up land and almost nobody lived there (GHSL 2025, 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. The GHSL 2025 epoch is a projection made from 2020 and earlier data.

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)
24 Jul 25.3 °C 24 % 49 km/h 1.0 mm Low 9
25 Jul 25.8 °C 22 % 51 km/h 0.6 mm Moderate 16
26 Jul 24.8 °C 24 % 43 km/h 1.7 mm Low 9
27 Jul 22.0 °C 20 % 39 km/h 0.5 mm Moderate 16
28 Jul 23.9 °C 15 % 46 km/h 0.0 mm High 22
29 Jul 23.5 °C 20 % 40 km/h 1.2 mm Moderate 13
30 Jul 23.7 °C 24 % 32 km/h 1.6 mm Low 9
31 Jul 26.0 °C 15 % 25 km/h 0.0 mm Moderate 19
1 Aug after 28.1 °C 10 % 48 km/h 0.0 mm High 32
2 Aug after 23.4 °C 11 % 51 km/h 0.0 mm High 34
3 Aug after 18.3 °C 16 % 31 km/h 0.0 mm High 28
4 Aug after 21.0 °C 13 % 38 km/h 0.0 mm High 29
5 Aug after 24.0 °C 9 % 34 km/h 0.0 mm High 31
6 Aug after 26.4 °C 9 % 43 km/h 0.0 mm High 35
7 Aug after 26.4 °C 10 % 42 km/h 0.0 mm High 36
8 Aug after 25.9 °C 12 % 49 km/h 0.2 mm Very high 39
9 Aug after 25.4 °C 11 % 46 km/h 0.0 mm Very high 39
10 Aug after 26.0 °C 10 % 48 km/h 0.0 mm Very high 40

Before and after, from space

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

Before · 17 Jul 2026
After · 7 Aug 2026

If the day is cloudy, change the date: each satellite passes once a day. In false colour the burnt ground looks brown or red.

The smoke

CAMS · Copernicus

On 28 July 2026 the air beside the fire reached 38 µg/m³ of PM2.5. That day averaged 28: 1.8 times the WHO daily guideline (15).

PM2.5 peak38 µg/m³
Days over the guideline5 days
PM1053 µg/m³
Optical depth0.69
22232425262728293031123
Good Fair Moderate Poor Very poor Extremely poor

Particles from the Copernicus CAMS model at the centre of the perimeter; these are not measurements in each town. The pale bar is the worst hour, the solid one the daily average.

Open-Meteo.com (CC BY 4.0) · Copernicus Atmosphere Monitoring Service (CAMS)

Detections table · 15Every 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 Doublesprings Fire last?
The official perimeter only gives the start date (24 July 2026). The end comes from the heat detections inside the perimeter: it burned until 31 July 2026 (8 days from 24 July 2026), 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 687 hectares (6.9 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?
The fire only entered Custer (687 ha, 0.0 %).
What was the weather like?
During the fire the temperature reached 26.0 °C, humidity dropped to 15 % and gusts hit 51 km/h. The fire danger index (FWI) reached 22, class 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.

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: NIFC WFIGS (United States), 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. 15 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 2025, 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.