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Sand Lake Fire, June 2025 Southeast Fairbanks

Out · last detection 23 Jun 2025, 20:43 UTC

The fire started on 21 June 2025 in Southeast Fairbanks, United States, and satellites saw it burning for 3 days. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 2,571 hectares, spread across a single county.

It is the 230th largest in Alaska since 2016 (of 472 with a page). Number 116 in United States in 2025, of 325.

Compare with…

Suggestions: Oregon Lakes · 2019Central Creek Airstrip · 2022Twelvemile Lake · 2025Volkmar River · 2022

Burnt area
2,571ha
official perimeter (MTBS / NIFC)
Duration
≈ 3days
21 Jun 2025 – 23 Jun 2025
Counties hit
1
counties
Started on
21 Jun
2025
Heat detections
279
in a single hotspot: 124 MW
Danger at start
9
Low · FWI index
Average daily power
1.2GW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 21 Jun23 Jun
23 Jun 2025

How it evolved, day by day

21 Jun 2025 · 1,340 MW · 42 22 Jun 2025 · 1,977 MW · 178 23 Jun 2025 · 263 MW · 59
21 Jun 22 Jun 23 Jun

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
23km/h · peak gust
19%lowest humidity

It had gone 0 days without rain (1 mm or more) when it started. Rain came after the fire: 1.2 mm on 24 Jun.

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 1.6% of the area of London (26 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. Southeast Fairbanks where it started
    2,551 ha reached on 21 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.

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)
21 Jun 28.3 °C 19 % 23 km/h 0.0 mm Low 9
22 Jun 26.4 °C 29 % 22 km/h 0.3 mm Moderate 14
23 Jun 20.4 °C 57 % 22 km/h 5.2 mm Low 9
24 Jun after 19.2 °C 60 % 27 km/h 1.2 mm Very low 0

Its twins: fires that started in the same weather

It started with an FWI of 9.4, a minimum humidity of 19% and rain the day before. Fires in the area that started in weather like this since 2016: 11.

FWI at the start 9.4
Minimum humidity 19 %
Days without rain 0
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Oregon Lakes Fire, April 2019
9,677 ha 31 days FWI 11.5 Min. humidity 24 % 90 km away, in 2019

First rain (1 mm or more) after it ended: 17.0 mm on 31 May.

See its page Compare with this fire

What happened to them

Fires in the area that started in similar weather: 11. With fewer than 15 we give no figures: they would be more noise than signal.

This is a bank of analogues: it shows what usually happens, not what will happen. With fewer than 15 twins we give no figures. How we calculate it

How it ended

1.2 mmfirst rain
24 Junthe day after it ended
23km/h · max. gust

It was considered over on 23 Jun, and on 24 Jun 1.2 mm fell. We do not know whether the rain or the firefighters put it out.

Weather on this page: Open-Meteo.com (CC BY 4.0) · Copernicus Climate Change Service (ERA5)

How a twin is chosen

  • Same area: fires that have already ended, less than 250 km from this one, since 2016.
  • Same start: we compare the FWI on the first day, the minimum humidity that day and the run of days without rain before it. The slider sets how much they may differ.
  • Only pages with final weather data (ERA5 reanalysis) calculated in the same way as this fire’s; agricultural and grass burns and pages with data under review are left out.
  • Fires burning at the same time as this one (a week before or after) are left out: they share the same spell of weather and do not count as a precedent.
  • They are sorted by similarity, and the outlines of the first five are drawn.

How we calculate it

Before and after, from space

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

Before · 14 Jun 2025
After · 30 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 23 June 2025 the air beside the fire reached 272 µg/m³ of PM2.5. That day averaged 169: 11 times the WHO daily guideline (15).

PM2.5 peak272 µg/m³
Days over the guideline4 days
PM10278 µg/m³
Optical depth3.04
19 Jun21 Jun23 Jun
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 · 279Every 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 Sand Lake Fire last?
The official perimeter only gives the start date (21 June 2025). The end comes from the heat detections inside the perimeter: it burned until 23 June 2025 (3 days from 21 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 2,571 hectares (25.7 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?
The fire only entered Southeast Fairbanks (2,551 ha, 0.0 %).
What was the weather like?
During the fire the temperature reached 28.3 °C, humidity dropped to 19 % and gusts hit 23 km/h. The fire danger index (FWI) reached 14, 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 With cross-checks and a citable version

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. 279 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.