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Bartlett Fire, July 2025 Humboldt

Out · last measured on 4 Jul 2025

The fire started on 4 July 2025 in Humboldt, United States, and satellites saw it burning for 1 day. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 2,497 hectares, spread across a single county.

It is the 100th largest in Nevada since 2016 (of 237 with a page). Number 122 in United States in 2025, of 327.

We have the official perimeter (MTBS / NIFC) for this fire, but not yet its hotspots: NASA publishes the yearly hotspot archive only once the year closes. The page picks them up automatically when they are available.

Burnt area
2,497ha
official perimeter (MTBS / NIFC)
Duration
1day
4 Jul 2025 – 4 Jul 2025
Municipalities hit
1
counties
Started on
4 Jul
2025
Danger at start
51
Extreme · FWI index

Where it burned

The weather it burned in

27°high
50km/h · peak gust
15%lowest humidity

It had gone 12 days 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.

What happened to each town

  1. Humboldt where it started
    2,503 ha
    0.1 %

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)
4 Jul 26.9 °C 15 % 50 km/h 0.1 mm Extreme 51
5 Jul after 27.4 °C 16 % 28 km/h 0.0 mm Very high 43
6 Jul after 31.4 °C 12 % 27 km/h 0.0 mm Very high 42
7 Jul after 35.3 °C 7 % 30 km/h 0.0 mm Very high 49
8 Jul after 33.7 °C 9 % 42 km/h 0.0 mm Extreme 55
9 Jul after 30.2 °C 8 % 46 km/h 0.0 mm Extreme 59
10 Jul after 31.8 °C 14 % 23 km/h 0.0 mm Very high 47
11 Jul after 32.9 °C 16 % 27 km/h 0.0 mm Very high 46
12 Jul after 35.8 °C 13 % 27 km/h 0.0 mm Very high 46
13 Jul after 37.2 °C 9 % 27 km/h 0.0 mm Very high 48
14 Jul after 38.0 °C 9 % 39 km/h 0.0 mm Extreme 50

Before and after, from space

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

Before · 27 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 2 July 2025 the air beside the fire reached 21 µg/m³ of PM2.5, but no daily average passed the WHO guideline (15).

PM2.5 peak21 µg/m³
Days over the guideline0 days
PM10167 µg/m³
Optical depth0.23
234567
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)

Other fires nearby

All fires in United States ›

Frequently asked questions

How long did the Bartlett fire last?
It burned between 4 July 2025 and 4 July 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 2,497 hectares (25.0 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?
The fire only entered Humboldt (2,503 ha, 0.1 %).
What was the weather like?
During the fire the temperature reached 26.9 °C, humidity dropped to 15 % and gusts hit 50 km/h. The fire danger index (FWI) reached 51, 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

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.