Weather & Climate in Custer, MT

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

Custer experiences four distinct seasons with an average annual temperature of 47°F (8°C). Winters average 24°F in January while summers reach 73°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 14.9 inches (drier than the 38-inch national average). The area receives 37.1 inches of snow annually, a moderate snowfall amount. Air quality is rated Good with a median AQI of 36. 91% of days have good air quality. The city sits at an elevation of 2,742 feet.

Temperature

24°F Jan (-5°C) 73°F Jul (23°C)

Annual Average	47.2°F
	13% below US avg
January Average	24°F (-5°C)
July Average	73°F (23°C)
Sunny Days	273 days/yr

Geography

Elevation	2,742 ft (836 m)
Area	0.3 sq mi (0.7 km²)
Population Density	484/sq mi
Coordinates	46.1292°N, 107.5555°W
Timezone	America/Denver
County	Treasure County County
Nearest Airport	Billings Logan International (BIL) 52 miles away

Precipitation & Snow

Annual Rainfall 14.9"

61% below US avg

Snowfall 37.1"

Wettest Month (May) 2.60"

Driest Month (Feb) 0.47"

Air Quality

AQI Median	36.0
Rating	Good
Good Days %	90.9%
Unhealthy Days	2

Natural Hazard Risk

Overall Risk	Very Low
Risk Score	0.5 / 100
Social Vulnerability	10.6 / 100
Community Resilience	4.7 / 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	Very Low
Ice Storm	Very Low
Drought	Very Low
Cold Wave	Very Low
Landslide	Very Low

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

Earthquake History

11 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M4.0.

Aug 22, 2009	20 km SSE of Birney, Montana	M4.0	140 km	14 km
Jul 6, 2021	27 km SSE of Melstone, Montana	M3.6	31 km	10 km
Dec 23, 1991	10 km SW of Colstrip, Montana	M3.6	74 km	5 km
Jul 21, 2023	Eastern Montana	M3.2	123 km	5 km
May 21, 2013	32 km NE of Melstone, Montana	M2.8	71 km	7 km
Mar 30, 2018	20 km NNE of Sheridan, Wyoming	M2.8	142 km	5 km
Jan 15, 2023	6 km NE of Ashland, Montana	M2.8	119 km	11 km
May 19, 2017	6 km ESE of Birney, Montana	M2.7	127 km	3 km
Jan 6, 2016	27 km ENE of Lovell, Wyoming	M2.6	136 km	12 km
Jun 2, 2019	14 km WSW of Birney, Montana	M2.6	116 km	5 km
Apr 22, 2018	8 km ENE of Ashland, Montana	M2.6	122 km	5 km

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

Tornado History

43 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF3. Total: 5 injuries.

Date	Rating	Distance	Path	Fatalities
Jun 16, 1965	EF3	82 km	20.6 mi	0
Jun 20, 2010	EF2	80 km	0.7 mi	0
May 4, 1986	EF2	47 km	0.1 mi	0
Jul 2, 1958	EF2	80 km	0.5 mi	0
Jun 7, 2018	EF1	88 km	0.8 mi	0
May 21, 2016	EF1	40 km	2.0 mi	0
Jun 22, 1996	EF1	42 km	4.0 mi	0
Jul 9, 1991	EF1	45 km	0.1 mi	0
Jun 21, 1991	EF1	87 km	0.2 mi	0
Jun 21, 1991	EF1	35 km	0.2 mi	0
May 24, 1990	EF1	68 km	0.2 mi	0
Jun 21, 1984	EF1	94 km	1.0 mi	0
Jun 14, 1980	EF1	70 km	0.1 mi	0
Jul 6, 1955	EF1	64 km	2.0 mi	0
Jul 6, 1955	EF1	25 km	2.0 mi	0
May 31, 2014	EF0	90 km	0.1 mi	0
Jul 8, 2013	EF0	59 km	0.5 mi	0
Jun 6, 2011	EF0	72 km	0.3 mi	0
Aug 26, 2004	EF0	77 km	—	0
Jul 26, 2003	EF0	78 km	2.5 mi	0

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

Wildfire History

20 wildfires (100+ acres) recorded within 100 km. Largest: RICHARD SPRING (168,765 acres, 2021).

Year	Name	Acres Burned	Distance
2021	RICHARD SPRING	168,765	92 km
1984	HAWK CREEK	157,778	57 km
2012	CHALKY	132,680	72 km
2008	DUNN MTN. ASSIST	105,494	50 km
2006	PINE RIDGE COMPLEX	103,074	15 km
2006	BUNDY RAILROAD	91,575	30 km
2012	SARPY HILLS COMPLEX	83,942	58 km
2021	P F	66,375	36 km
1994	BABY DEAN	61,955	91 km
2020	SARPY	51,619	67 km
2012	DELPHIA	40,396	55 km
2020	BOBCAT	31,020	66 km
1999	FISHEL CREEK	28,611	59 km
2003	LITTLEHAWK	27,926	72 km
2021	MUSSELSHELL TRAIL RD	22,723	19 km
1988	EARLYBIRD	21,730	96 km
2012	DAHL	21,448	79 km
2011	BLACK SPRINGS COMPLEX	19,473	78 km
2022	BUSMAN ROAD	12,584	23 km
1996	ROLLOVER	10,743	80 km

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

Monthly Weather

Month	Avg Temperature	Precipitation	Summary
January	24°F (-5°C)	0.6 in	Coldest
February	26°F (-3°C)	0.5 in	Driest
March	36°F (2°C)	0.8 in
April	46°F (8°C)	1.6 in
May	56°F (13°C)	2.6 in	Wettest
June	65°F (18°C)	2.1 in
July	73°F (23°C)	1.2 in	Warmest
August	71°F (22°C)	1.1 in
September	60°F (15°C)	1.5 in
October	48°F (9°C)	1.1 in
November	34°F (1°C)	0.6 in
December	24°F (-4°C)	0.6 in

Custer has a seasonal temperature swing of 49°F / from 24°F in January to 73°F in July. Total annual precipitation is 14.5 inches, with May being the wettest month (2.6") and February the driest (0.5").

View full profile of Custer, MT →