How long did the Moss Ranch fire last?

According to the heat detections seen by satellite inside the perimeter, it burned from 23 July 2019 to 30 July 2019 (8 days). The perimeter dates it from 23 July 2019 to 23 July 2019.

How much area did it burn?

The official perimeter published by United States agencies (MTBS / NIFC) is 2,196 hectares (22.0 km²). Other tallies, such as daily incident reports, may give slightly different figures.

Which counties burned?

The fire only entered Sanders (2,185 ha, 0.3 %).

What was the weather like?

During the fire the temperature reached 35.6 °C, humidity dropped to 15 % and gusts hit 64 km/h. The fire danger index (FWI) reached 44, class Very 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.

US · United States · 2019-07-23 → 2019-07-30

Moss Ranch Fire, July 2019 Sanders

Out · last detection 30 Jul 2019, 09:15 UTC

The fire started on 23 July 2019 in Sanders, United States, and satellites saw it burning for 8 days. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 2,196 hectares, spread across a single county.

It is the 102th largest in Montana since 2016 (of 302 with a page). Number 122 in United States in 2019, of 367.

Compare with…

Suggestions: Middle Ridge · 2023 Race Horse Gulch · 2016 Knowles · 2025 River Road East · 2023

Burnt area: 2,196ha; official perimeter (MTBS / NIFC)
Duration: 8days; 23 Jul 2019 – 30 Jul 2019
Municipalities hit: 1; counties
Started on: 23 Jul; 2019
Heat detections: 138; in a single hotspot: 321 MW
Danger at start: 31; High · FWI index
Average daily power: 274MW; detected power per day, on average

Play back 30 Jul 2019

HOTSPOTS BY DAY 23 Jul30 Jul

How it evolved, day by day

23 Jul 25 Jul 27 Jul 29 Jul

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

The weather it burned in

36°high

64km/h · peak gust

15%lowest humidity

It had gone 4 days without rain (1 mm or more) when it started. Rain came after the fire: 1.3 mm on 2 Aug.

This area had burned before

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

How big is it?

It burned the equivalent of 1.4% of the area of London (22 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 town

Sanders where it started

2,185 ha reached on 23 Jul

0.3 %

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)
23 Jul	35.6 °C	17 %	44 km/h	0.9 mm	High 31
24 Jul	24.7 °C	18 %	53 km/h	0.0 mm	High 37
25 Jul	28.6 °C	17 %	36 km/h	0.0 mm	High 33
26 Jul	32.1 °C	15 %	26 km/h	0.0 mm	High 33
27 Jul	30.1 °C	18 %	64 km/h	0.0 mm	Very high 44
28 Jul	28.1 °C	18 %	30 km/h	0.0 mm	High 35
29 Jul	30.5 °C	15 %	26 km/h	0.0 mm	High 34
30 Jul	30.5 °C	19 %	45 km/h	0.0 mm	Very high 41
31 Jul after	33.1 °C	14 %	29 km/h	0.0 mm	High 37
1 Aug after	33.3 °C	11 %	32 km/h	0.0 mm	Very high 42
2 Aug after	33.9 °C	17 %	40 km/h	1.3 mm	Very high 40

Before and after, from space

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

↔

Before · 16 Jul 2019

After · 6 Aug 2019

Before After

If the day is cloudy, change the date: each satellite passes once a day. In false colour the burnt ground looks brown or red.

Detections table · 138Every 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 time	Satellite	FRP (MW)	Lat	Lon

Other fires nearby

All fires in United States ›

Frequently asked questions

How long did the Moss Ranch fire last?: According to the heat detections seen by satellite inside the perimeter, it burned from 23 July 2019 to 30 July 2019 (8 days). The perimeter dates it from 23 July 2019 to 23 July 2019.
How much area did it burn?: The official perimeter published by United States agencies (MTBS / NIFC) is 2,196 hectares (22.0 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?: The fire only entered Sanders (2,185 ha, 0.3 %).
What was the weather like?: During the fire the temperature reached 35.6 °C, humidity dropped to 15 % and gusts hit 64 km/h. The fire danger index (FWI) reached 44, class Very 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

NASA FIRMS ↗
NIFC · Fire maps ↗

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.

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What do you think is wrong?

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What really happened?

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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.

How we know this

Perimeter: MTBS (US Geological Survey and US Forest Service), official.
Dates adjusted with the VIIRS detections inside the perimeter, which said 23 July 2019 to 23 July 2019. 138 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.

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.

Where it burned