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Log Fire, August 2025 Siskiyou

Out · last detection 27 Aug 2025, 21:58 UTC

The fire started on 26 August 2025 in Siskiyou, United States, and satellites saw it burning for 1 day. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 473 hectares, spread across a single county.

It is the 407th largest in California since 2016 (of 442 with a page). Number 306 in United States in 2025, of 327.

Burnt area
473ha
official perimeter (MTBS / NIFC)
Duration
1day
26 Aug 2025 – 26 Aug 2025
Municipalities hit
1
counties
Started on
26 Aug
2025
Heat detections
104
in a single hotspot: 64 MW
Danger at start
20
Moderate · FWI index
Energy released
31MW
sum of detected power

Where it burned

HOTSPOTS BY DAY 26 Aug26 Aug

How it evolved, day by day

27

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
45km/h · peak gust
13%lowest humidity

It had gone 0 days without rain (1 mm or more) when it started. Rain came after the fire: 3.1 mm on 6 Sept.

This area had burned before

13% of the perimeter overlaps earlier fires recorded since 2016: 39 ha in 2017, 23 ha in 2021.

What happened to each town

  1. Siskiyou where it started
    468 ha reached on 27 Aug
    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)
26 Aug 26.9 °C 31 % 35 km/h 0.6 mm Moderate 20
27 Aug after 25.7 °C 27 % 41 km/h 0.1 mm High 26
28 Aug after 28.1 °C 13 % 37 km/h 0.0 mm High 35
29 Aug after 25.9 °C 22 % 40 km/h 0.0 mm High 34
30 Aug after 26.5 °C 19 % 35 km/h 0.0 mm High 34
31 Aug after 26.8 °C 18 % 37 km/h 0.0 mm High 35
1 Sept after 28.0 °C 15 % 34 km/h 0.0 mm High 35
2 Sept after 27.5 °C 23 % 45 km/h 2.1 mm Moderate 17
3 Sept after 27.7 °C 25 % 31 km/h 0.0 mm High 24
4 Sept after 28.0 °C 24 % 30 km/h 0.1 mm High 26
5 Sept after 26.6 °C 25 % 34 km/h 0.3 mm High 28
6 Sept after 22.8 °C 37 % 37 km/h 3.1 mm Low 6

Before and after, from space

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

Before · 19 Aug 2025
After · 2 Sept 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 29 August 2025 the air beside the fire reached 78 µg/m³ of PM2.5. That day averaged 40: 2.7 times the WHO daily guideline (15).

PM2.5 peak78 µg/m³
Days over the guideline3 days
PM1079 µg/m³
Optical depth0.61
242526272829
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 · 104Every 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 Log fire last?
It burned between 26 August 2025 and 26 August 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 473 hectares (4.7 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?
The fire only entered Siskiyou (468 ha, 0.0 %).
What was the weather like?
During the fire the temperature reached 28.1 °C, humidity dropped to 13 % and gusts hit 45 km/h. The fire danger index (FWI) reached 35, 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

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
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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.

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.