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South Mountain Fire, June 2026 Tooele

Out · last detection 9 Jun 2026, 09:39 UTC

The fire started on 9 June 2026 in Tooele, United States, and satellites saw it burning for 1 day. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 755 hectares, spread across a single county.

It is the 123th largest in Utah since 2016 (of 165 with a page). Number 300 in United States in 2026, of 419.

The power measured by the satellite is low (10.3 MW in the strongest hotspot), more typical of grass or stubble burning, or a slow surface fire, than of a large crown fire.

Compare with…

Suggestions: Carrington Island · 2017Bald Mountain · 2018Jacob City · 2022Ellerbeck · 2018

Burnt area
755ha
official perimeter (MTBS / NIFC)
Duration
≈ 1day
9 Jun 2026 – 9 Jun 2026
Counties hit
1
counties
Started on
9 Jun
2026
Heat detections
48
in a single hotspot: 10 MW
Danger at start
25
High · FWI index
Average daily power
176MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 9 Jun9 Jun

How it evolved, day by day

9 Jun 2026 · 176 MW · 48

Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.

The weather it burned in

24°high
42km/h · peak gust
19%lowest humidity

It had gone one day 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.

How big is it?

10 km
It burned the equivalent of 0.5% of the area of London (7.6 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. Tooele where it started
    754 ha reached on 9 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)
9 Jun 23.7 °C 19 % 42 km/h 0.6 mm High 25
10 Jun after 25.7 °C 11 % 59 km/h 0.0 mm Very high 38
11 Jun after 20.5 °C 18 % 45 km/h 0.0 mm High 32
12 Jun after 27.6 °C 11 % 36 km/h 0.0 mm Very high 39
13 Jun after 26.0 °C 17 % 40 km/h 0.0 mm Very high 46
14 Jun after 26.6 °C 13 % 42 km/h 0.0 mm Very high 43
15 Jun after 28.3 °C 12 % 41 km/h 0.0 mm Very high 44
16 Jun after 31.3 °C 9 % 41 km/h 0.0 mm Extreme 53
17 Jun after 31.1 °C 9 % 46 km/h 0.0 mm Extreme 59
18 Jun after 28.5 °C 10 % 35 km/h 0.0 mm Very high 49
19 Jun after 32.8 °C 9 % 35 km/h 0.0 mm Very high 44

Its twins: fires that started in the same weather

It started with an FWI of 24.7, a minimum humidity of 19% and 1 day without rain. Fires in the area that started in weather like this since 2016: 27.

FWI at the start 24.7
Minimum humidity 19 %
Days without rain 1
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Carrington Island Fire, May 2017
584 ha 3 days FWI 25.8 Min. humidity 18 % 62 km away, in 2017

First rain (1 mm or more) after it ended: none in the following ten days.

See its page Compare with this fire

What happened to them

3 days
median duration
1,092 ha
median area
52 %
went past 1,000 ha
2.8 mm
rain at the end (median; 23 of 27 had it)

It burned an area similar to its twins (755 ha against a median of 1,092 ha) and lasted 1 day, against 3 days.

In 4 of 27, not even 1 mm fell in the ten days after the end: they went out without rain. In the rest, the first rainy day brought a median of 2.8 mm.

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

—first rain
—no rain in ten days
42km/h · max. gust

It was considered over on 9 Jun, and not even 1 mm fell in the following ten days: it went out without rain. Twins with rain when they ended: 23 of 27, with a median of 2.8 mm.

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 · 2 Jun 2026
After · 16 Jun 2026

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 10 June 2026 the air beside the fire reached 83 µg/m³ of PM2.5. That day averaged 39: 2.6 times the WHO daily guideline (15).

PM2.5 peak83 µg/m³
Days over the guideline5 days
PM10374 µg/m³
Optical depth0.30
7 Jun9 Jun11 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 · 48Every 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 South Mountain Fire last?
The official perimeter only gives the start date (9 June 2026). The end comes from the heat detections inside the perimeter: it burned until 9 June 2026 (1 day from 9 June 2026), 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 755 hectares (7.6 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?
The fire only entered Tooele (754 ha, 0.0 %).
What was the weather like?
During the fire the temperature reached 23.7 °C, humidity dropped to 19 % and gusts hit 42 km/h. The fire danger index (FWI) reached 25, 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.
How did the fires that started in similar weather in this area end?
Fires less than 250 km away that started since 2016 with a similar FWI, humidity and dry spell: 27. Their median duration was 3 days and their median area 1,092 ha; 52 % went past 1,000 ha. In 4 of 27, not even 1 mm fell in the ten days after the end: they went out without rain. In the rest, the first rainy day brought a median of 2.8 mm.

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. 48 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.