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Duncan Fire, July 2026 Owyhee

Out · last detection 24 Jul 2026, 22:01 UTC

The fire started on 24 July 2026 in Owyhee, United States, and satellites saw it burning for 1 day. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 6,622 hectares, spread across a single county.

It is the 53th largest in Idaho since 2016 (of 379 with a page). Number 77 in United States in 2026, of 423.

The power measured by the satellite is low (18.4 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…
Burnt area
6,622ha
official perimeter (MTBS / NIFC)
Duration
≈ 1day
24 Jul 2026 – 24 Jul 2026
Counties hit
1
counties
Started on
24 Jul
2026
Heat detections
80
in a single hotspot: 18 MW
Danger at start
58
Extreme · FWI index
Average daily power
628MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 24 Jul24 Jul

How it evolved, day by day

24 Jul 2026 · 628 MW · 80

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

The weather it burned in

39°high
33km/h · peak gust
6%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 4.2% of the area of London (66 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. Owyhee where it started
    6,598 ha reached on 24 Jul
    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.

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 38.8 °C 6 % 33 km/h 0.0 mm Extreme 58
25 Jul after 37.3 °C 8 % 43 km/h 0.0 mm Very extreme 73
26 Jul after 35.1 °C 9 % 37 km/h 0.0 mm Extreme 64
27 Jul after 33.1 °C 13 % 36 km/h 0.0 mm Extreme 56
28 Jul after 34.9 °C 10 % 38 km/h 0.0 mm Extreme 64
29 Jul after 33.3 °C 14 % 31 km/h 0.1 mm Extreme 56
30 Jul after 36.4 °C 10 % 35 km/h 0.0 mm Extreme 59
31 Jul after 38.8 °C 3 % 26 km/h 0.0 mm Extreme 55
1 Aug after 39.5 °C 4 % 43 km/h 0.0 mm Very extreme 75
2 Aug after 29.8 °C 15 % 43 km/h 0.0 mm Extreme 62
3 Aug after 26.5 °C 12 % 37 km/h 0.0 mm Extreme 58

Before and after, from space

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

Before · 17 Jul 2026
After · 31 Jul 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 27 July 2026 the air beside the fire reached 95 µg/m³ of PM2.5. That day averaged 56: 3.7 times the WHO daily guideline (15).

PM2.5 peak95 µg/m³
Days over the guideline4 days
PM10101 µg/m³
Optical depth0.85
222324252627
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 · 80Every 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 Duncan 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 24 July 2026 (1 day 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 6,622 hectares (66.2 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?
The fire only entered Owyhee (6,598 ha, 0.3 %).
What was the weather like?
During the fire the temperature reached 38.8 °C, humidity dropped to 6 % and gusts hit 33 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

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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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. 80 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.

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.