Weather & Climate in St. Onge, SD

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

St. Onge experiences four distinct seasons with an average annual temperature of 48°F (9°C). Winters average 25°F in January while summers reach 74°F in July. The area gets 311 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 18.0 inches (drier than the 38-inch national average). The area receives 42.2 inches of snow annually, making winter weather a significant factor for residents. Air quality is rated Good with a median AQI of 35. The city sits at an elevation of 3,433 feet.

Temperature

25°F Jan (-4°C) 74°F Jul (23°C)

Annual Average	47.9°F
	11% below US avg
January Average	25°F (-4°C)
July Average	74°F (23°C)
Sunny Days	311 days/yr

Geography

Elevation	3,433 ft (1,046 m)
Area	1.4 sq mi (3.5 km²)
Population Density	34/sq mi
Coordinates	44.5457°N, 103.7199°W
Timezone	America/Chicago
County	Lawrence County County
Nearest Airport	Ellsworth Afb (RCA) 41 miles away

Precipitation & Snow

Annual Rainfall 18.0"

53% below US avg

Snowfall 42.2"

Wettest Month (Jun) 3.74"

Driest Month (Jan) 0.79"

Air Quality

AQI Median	35.0
Rating	Good

Natural Hazard Risk

Overall Risk	Relatively Low
Risk Score	49.3 / 100
Social Vulnerability	35.5 / 100
Community Resilience	54.0 / 100

Hazard Breakdown

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

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

Earthquake History

18 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M4.2.

Sep 25, 2009	15 km E of Alzada, Montana	M4.2	65 km	5 km
Feb 6, 1996	13 km WNW of Hill City, South Dakota	M3.7	63 km	5 km
Mar 9, 2025	7 km W of Fairburn, South Dakota	M3.6	102 km	5 km
Dec 12, 2013	10 km WSW of Hermosa, South Dakota	M3.5	87 km	5 km
Mar 26, 2021	10 km E of Edgemont, South Dakota	M3.4	138 km	5 km
Feb 7, 2007	11 km WSW of Wasta, South Dakota	M3.1	107 km	5 km
Jun 29, 2024	22 km ESE of Hill View Heights, Wyoming	M3.0	88 km	10 km
Jan 16, 2012	25 km E of Buffalo Gap, South Dakota	M3.0	131 km	5 km
Jun 16, 2024	7 km NNE of Buffalo Gap, South Dakota	M2.9	117 km	8 km
Mar 18, 1994	4 km SSW of Hot Springs, South Dakota	M2.8	129 km	5 km
Jan 5, 2004	28 km SSE of Hill View Heights, Wyoming	M2.8	108 km	5 km
Jul 17, 2016	15 km NNE of Oelrichs, South Dakota	M2.8	145 km	5 km
Sep 5, 1993	4 km NNW of Central City, South Dakota	M2.7	17 km	5 km
Jul 29, 2013	18 km SE of Ekalaka, Montana	M2.6	146 km	8 km
Jun 8, 2025	19 km NW of Wasta, South Dakota	M2.6	97 km	5 km
Jun 16, 2021	15 km N of Quinn, South Dakota	M2.6	137 km	5 km
Nov 5, 1991	1 km ESE of Lead, South Dakota	M2.5	22 km	0 km
Jan 24, 2004	8 km WSW of Green Valley, South Dakota	M2.5	74 km	5 km

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

Tornado History

167 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF4. Total: 42 injuries.

Date	Rating	Distance	Path	Fatalities
Jul 7, 1969	EF4	82 km	1.8 mi	0
Jun 28, 2018	EF3	99 km	3.6 mi	0
Jun 29, 1993	EF3	33 km	3.0 mi	0
May 11, 1991	EF3	55 km	2.0 mi	0
Jun 25, 1975	EF3	61 km	11.5 mi	0
Jul 18, 1965	EF3	15 km	0.1 mi	0
Jul 12, 1965	EF3	53 km	20.8 mi	0
Jul 18, 1963	EF3	53 km	2.3 mi	0
Jul 6, 2020	EF2	39 km	5.1 mi	0
Jul 6, 2020	EF2	41 km	2.1 mi	0
Jun 28, 2018	EF2	99 km	2.3 mi	0
Jun 28, 2018	EF2	97 km	6.6 mi	0
Jun 13, 2016	EF2	85 km	7.4 mi	0
Jun 19, 2015	EF2	58 km	19.7 mi	0
Jun 13, 2014	EF2	70 km	16.5 mi	0
Jul 13, 2009	EF2	56 km	9.4 mi	0
Jul 12, 1993	EF2	21 km	2.0 mi	0
May 11, 1991	EF2	57 km	1.0 mi	0
May 10, 1985	EF2	67 km	1.0 mi	0
Jun 28, 1972	EF2	1 km	0.1 mi	0

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

Wildfire History

20 wildfires (100+ acres) recorded within 100 km. Largest: JASPER (82,298 acres, 2000).

Year	Name	Acres Burned	Distance
2000	JASPER	82,298	82 km
2012	OIL CREEK	63,182	77 km
1988	GALENA	16,936	89 km
2006	THORN DIVIDE COMPLEX	15,261	87 km
2002	BATTLE CREEK	15,034	76 km
1990	SWEDLUND	14,673	97 km
2015	SHEEP DRAW	13,837	93 km
2001	ELK MOUNTAIN 2	13,758	94 km
2001	ROGERS SHACK	11,794	100 km
2002	GRIZZLY GULCH	11,487	22 km
2011	WHOOPUP	7,377	95 km
2022	FISH	7,045	54 km
2016	KARA CREEK	6,543	79 km
1988	NEW HAVEN	6,118	94 km
2000	WOOD DRAW	5,792	90 km
1988	SHORT PINES	5,516	96 km
2004	BASIN DRAW	4,655	46 km
2008	BASELINE BUGS PB	4,315	61 km
1988	MCDOWELLE	4,096	91 km
1988	WESTBERRY TRAIL	3,944	61 km

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

Monthly Weather

Month	Avg Temperature	Precipitation	Summary
January	25°F (-4°C)	0.8 in	Coldest, Driest
February	27°F (-3°C)	0.9 in
March	35°F (2°C)	1.7 in
April	45°F (7°C)	2.6 in
May	56°F (13°C)	3.6 in
June	65°F (18°C)	3.7 in	Wettest
July	74°F (23°C)	2.3 in	Warmest
August	71°F (22°C)	2.0 in
September	60°F (16°C)	1.9 in
October	48°F (9°C)	1.7 in
November	34°F (1°C)	1.1 in
December	25°F (-4°C)	1.0 in

St. Onge has a seasonal temperature swing of 49°F / from 25°F in January to 74°F in July. Total annual precipitation is 23.4 inches, with June being the wettest month (3.7") and January the driest (0.8").

View full profile of St. Onge, SD →