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Lush Fire, June 2025 Yukon-Koyukuk

Out · last detection 4 Jul 2025, 23:59 UTC

The fire started on 19 June 2025 in Yukon-Koyukuk, United States, and satellites saw it burning for 16 days. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 10,800 hectares, spread across a single county.

It is the 97th largest in Alaska since 2016 (of 472 with a page). Number 33 in United States in 2025, of 327.

Compare with…
Burnt area
10,800ha
official perimeter (MTBS / NIFC)
Duration
≈ 16days
19 Jun 2025 – 4 Jul 2025
Counties hit
1
counties
Started on
19 Jun
2025
Heat detections
267
in a single hotspot: 123 MW
Danger at start
1
Very low · FWI index
Average daily power
425MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 19 Jun4 Jul
4 Jul 2025

How it evolved, day by day

19 Jun 2025 · 193 MW · 7 20 Jun 2025 · 228 MW · 5 21 Jun 2025 · 1,263 MW · 40 22 Jun 2025 · 571 MW · 44 23 Jun 2025 · 41 MW · 6 24 Jun 2025 · 25 MW · 3 1 Jul 2025 · 4 MW · 1 2 Jul 2025 · 57 MW · 5 3 Jul 2025 · 1,050 MW · 96 4 Jul 2025 · 822 MW · 60
19 Jun 21 Jun 23 Jun 1 Jul 3 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

27°high
45km/h · peak gust
32%lowest humidity

It had gone 0 days without rain (1 mm or more) when it started. Rain came after the fire: 1.0 mm on 6 Jul.

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 6.8% of the area of London (108 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. Yukon-Koyukuk where it started
    10,893 ha reached on 19 Jun
    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.

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)
19 Jun 25.5 °C 53 % 18 km/h 2.3 mm Very low 1
20 Jun 26.2 °C 45 % 17 km/h 0.4 mm Very low 4
21 Jun 24.6 °C 41 % 31 km/h 0.1 mm Low 9
22 Jun 22.9 °C 56 % 17 km/h 3.8 mm Very low 1
23 Jun 18.6 °C 79 % 31 km/h 9.9 mm Very low 0
24 Jun 19.7 °C 54 % 24 km/h 0.5 mm Very low 0
25 Jun 18.4 °C 67 % 23 km/h 7.5 mm Very low 0
26 Jun 17.8 °C 63 % 36 km/h 3.4 mm Very low 0
27 Jun 18.5 °C 55 % 31 km/h 0.0 mm Very low 1
28 Jun 21.5 °C 52 % 28 km/h 0.4 mm Very low 2
29 Jun 21.1 °C 49 % 32 km/h 0.2 mm Very low 4
30 Jun 21.8 °C 48 % 16 km/h 0.0 mm Very low 5
1 Jul 26.4 °C 37 % 32 km/h 0.0 mm Low 9
2 Jul 26.0 °C 41 % 45 km/h 0.3 mm Moderate 12
3 Jul 25.5 °C 36 % 38 km/h 0.0 mm Moderate 12
4 Jul 27.2 °C 32 % 28 km/h 0.0 mm Moderate 13
5 Jul after 27.8 °C 30 % 41 km/h 0.0 mm Moderate 17
6 Jul after 25.5 °C 42 % 26 km/h 1.0 mm Low 9

Before and after, from space

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

Before · 12 Jun 2025
After · 11 Jul 2025

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 20 June 2025 the air beside the fire reached 84 µg/m³ of PM2.5. That day averaged 34: 2.3 times the WHO daily guideline (15).

PM2.5 peak84 µg/m³
Days over the guideline3 days
PM1084 µg/m³
Optical depth0.97
171819202122
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 · 267Every 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 Lush Fire last?
The official perimeter only gives the start date (19 June 2025). The end comes from the heat detections inside the perimeter: it burned until 4 July 2025 (16 days from 19 June 2025), 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 10,800 hectares (108.0 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?
The fire only entered Yukon-Koyukuk (10,893 ha, 0.0 %).
What was the weather like?
During the fire the temperature reached 27.2 °C, humidity dropped to 32 % and gusts hit 45 km/h. The fire danger index (FWI) reached 13, class Moderate.
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
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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: 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. 267 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.