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Helpmejack Fire, June 2025 Yukon-Koyukuk, Northwest Arctic

Out · last detection 18 Jun 2025, 22:18 UTC

The fire started on 17 June 2025 in Yukon-Koyukuk, United States, and satellites saw it burning for 1 day. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 1,284 hectares, spread across 2 counties.

It is the 303th largest in Alaska since 2016 (of 472 with a page). Number 187 in United States in 2025, of 327.

Burnt area
1,284ha
official perimeter (MTBS / NIFC)
Duration
1day
17 Jun 2025 – 17 Jun 2025
Municipalities hit
2
counties
Started on
17 Jun
2025
Heat detections
99
in a single hotspot: 264 MW
Danger at start
16
Moderate · FWI index
Energy released
2.7GW
sum of detected power

Where it burned

18 Jun 2025
HOTSPOTS BY DAY 17 Jun17 Jun

How it evolved, day by day

1718

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
36km/h · peak gust
26%lowest humidity

It had gone 4 days without rain (1 mm or more) when it started. Rain came after the fire: 4.0 mm on 24 Jun.

This area had burned before

No earlier perimeters overlap this fire since 2016, when the satellite record begins.

What happened to each town

  1. Yukon-Koyukuk where it started
    1,205 ha reached on 17 Jun
    0.0 %
  2. Northwest Arctic
    148 ha reached on 18 Jun
    0.0 %

Burnt area inside each county, from crossing the official perimeter with administrative boundaries. The distance is from the town centre 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)
17 Jun 26.7 °C 26 % 36 km/h 0.0 mm Moderate 16
18 Jun after 26.5 °C 28 % 25 km/h 0.7 mm Moderate 13
19 Jun after 25.2 °C 34 % 28 km/h 0.1 mm Moderate 14
20 Jun after 24.1 °C 35 % 25 km/h 0.0 mm Moderate 14
21 Jun after 25.0 °C 34 % 34 km/h 2.2 mm Low 6
22 Jun after 22.3 °C 35 % 22 km/h 0.1 mm Low 10
23 Jun after 21.7 °C 50 % 36 km/h 7.2 mm Very low 1
24 Jun after 17.7 °C 59 % 20 km/h 4.0 mm Very low 0

Before and after, from space

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

Before · 10 Jun 2025
After · 24 Jun 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 19 June 2025 the air beside the fire reached 101 µg/m³ of PM2.5. That day averaged 56: 3.7 times the WHO daily guideline (15).

PM2.5 peak101 µg/m³
Days over the guideline3 days
PM10104 µg/m³
Optical depth0.74
151617181920
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 · 99Every 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 Helpmejack fire last?
It burned between 17 June 2025 and 17 June 2025: 1 day, according to the start date recorded by United States agencies (MTBS / NIFC) and the heat detections seen by satellite.
How much area did it burn?
The official perimeter published by United States agencies (MTBS / NIFC) is 1,284 hectares (12.8 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?
The fire entered 2 counties: Yukon-Koyukuk (1,205 ha, 0.0 %); Northwest Arctic (148 ha, 0.0 %).
What was the weather like?
During the fire the temperature reached 26.7 °C, humidity dropped to 26 % and gusts hit 36 km/h. The fire danger index (FWI) reached 16, 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

Satellite cross-check

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.

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.