Weather & Climate in Grass Range, MT

Temperature, precipitation, air quality, natural hazards, and monthly weather data.

Grass Range experiences four distinct seasons with an average annual temperature of 46°F (8°C). Winters average 26°F in January while summers reach 68°F in July. The area gets 273 sunny days per year, well above the U.S. average of 205 / making it one of the sunnier locations in the country. Annual precipitation totals 17.9 inches (drier than the 38-inch national average). The area receives 50.1 inches of snow annually, making winter weather a significant factor for residents. Air quality is rated Good with a median AQI of 26 / among the cleanest air in the country. The city sits at an elevation of 3,483 feet.

Temperature

26°F Jan (-4°C) 68°F Jul (20°C)

Annual Average	45.5°F
	16% below US avg
January Average	26°F (-4°C)
July Average	68°F (20°C)
Sunny Days	273 days/yr

Geography

Elevation	3,483 ft (1,062 m)
Area	0.1 sq mi (0.4 km²)
Population Density	693/sq mi
Coordinates	47.0261°N, 108.8031°W
Timezone	America/Denver
County	Petroleum County County
Nearest Airport	Billings Logan International (BIL) 85 miles away

Precipitation & Snow

Annual Rainfall 17.9"

53% below US avg

Snowfall 50.1"

Wettest Month (May) 3.19"

Driest Month (Feb) 0.35"

Air Quality

AQI Median	26.0
Rating	Good

Natural Hazard Risk

Overall Risk	Very Low
Risk Score	1.3 / 100
Social Vulnerability	27.4 / 100
Community Resilience	12.9 / 100

Hazard Breakdown

Tornado	Very Low
Earthquake	Very Low
Wildfire	Relatively Low
Flood	Very Low
Hail	Very Low
Strong Wind	Very Low
Heat Wave	Very Low
Winter Weather	Very Low
Lightning	Relatively Moderate
Ice Storm	Very Low
Drought	Very Low
Cold Wave	Relatively Low
Landslide	Very Low

Source: FEMA National Risk Index v1.20 (Dec 2025)

Earthquake History

6 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M3.6.

Jul 6, 2021	27 km SSE of Melstone, Montana	M3.6	109 km	10 km
Dec 5, 1991	15 km WSW of Hays, Montana	M3.0	103 km	10 km
May 21, 2013	32 km NE of Melstone, Montana	M2.8	102 km	7 km
Oct 16, 2011	Eastern Montana	M2.7	53 km	21 km
Jul 10, 2021	24 km SSE of Malta, Montana	M2.7	146 km	10 km
Jul 15, 2015	48 km E of Zortman, Montana	M2.5	117 km	23 km

Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.

Tornado History

55 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF2. Total: 3 injuries.

Date	Rating	Distance	Path	Fatalities
Jul 8, 2002	EF2	48 km	10.0 mi	0
Aug 14, 1999	EF2	47 km	5.0 mi	0
Jun 25, 1996	EF2	86 km	2.0 mi	0
May 4, 1986	EF2	93 km	0.1 mi	0
May 28, 1981	EF2	41 km	1.5 mi	0
Aug 7, 1962	EF2	43 km	2.0 mi	0
Aug 23, 1998	EF1	67 km	3.5 mi	0
May 10, 1977	EF1	92 km	0.1 mi	0
May 10, 1977	EF1	96 km	0.1 mi	0
Jun 3, 1971	EF1	93 km	2.3 mi	0
Jul 7, 1957	EF1	92 km	1.5 mi	0
Jul 7, 2020	EF0	27 km	0.2 mi	0
Jul 7, 2020	EF0	33 km	0.1 mi	0
Jun 27, 2019	EF0	99 km	0.4 mi	0
Jun 27, 2019	EF0	90 km	0.3 mi	0
Jun 27, 2019	EF0	97 km	0.1 mi	0
May 9, 2018	EF0	75 km	0.7 mi	0
Jul 8, 2013	EF0	85 km	0.5 mi	0
Jun 5, 2012	EF0	83 km	3.8 mi	0
Jun 28, 2005	EF0	42 km	0.3 mi	0

Source: NOAA Storm Prediction Center (EF0+, 1950–2024, US only).

Wildfire History

20 wildfires (100+ acres) recorded within 100 km. Largest: BRIDGE COULEE (222,571 acres, 2017).

Year	Name	Acres Burned	Distance
2017	BRIDGE COULEE	222,571	80 km
1984	HAWK CREEK	157,778	95 km
2012	DELPHIA	40,396	85 km
2017	SOUTH BREAKS	39,217	96 km
2006	LOST CREEK (BLACK PULASKI COMPLEX)	38,550	99 km
2006	SODA CREEK (BLACK PULASKI COMPLEX)	33,767	82 km
2020	BOBCAT	31,020	86 km
1999	FISHEL CREEK	28,611	79 km
2010	RAVEN	26,631	73 km
2021	TAYLOR	21,704	82 km
2012	DAHL	21,448	85 km
2006	LODGEPOLE (BLACK PULASKI COMPLEX)	15,248	78 km
2021	SOUTH MOCCASIN	12,727	57 km
2012	WOLF CREEK	12,168	70 km
2017	JULY	11,409	98 km
1994	CK CREEK	11,206	85 km
2019	RIDGETOP	10,316	65 km
1996	ALKALIE	10,044	75 km
2012	WELLS	9,921	89 km
2017	CRYING	7,497	69 km

Source: NIFC/IRWIN Wildfire Records (100+ acres).

Monthly Weather

Month	Avg Temperature	Precipitation	Summary
January	26°F (-4°C)	0.7 in
February	28°F (-2°C)	0.4 in	Driest
March	35°F (2°C)	0.8 in
April	44°F (7°C)	1.4 in
May	53°F (12°C)	3.2 in	Wettest
June	62°F (17°C)	2.7 in
July	68°F (20°C)	1.7 in	Warmest
August	68°F (20°C)	1.6 in
September	57°F (14°C)	1.3 in
October	47°F (8°C)	0.9 in
November	33°F (1°C)	0.5 in
December	26°F (-4°C)	0.6 in	Coldest

Grass Range has a seasonal temperature swing of 43°F / from 26°F in December to 68°F in July. Total annual precipitation is 15.7 inches, with May being the wettest month (3.2") and February the driest (0.4").

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