Weather & Climate in Interior, SD

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

Interior experiences four distinct seasons with an average annual temperature of 50°F (10°C). Winters average 26°F in January while summers reach 77°F in July. The area gets 302 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 19.6 inches (drier than the 38-inch national average). The area receives 38.0 inches of snow annually, a moderate snowfall amount. Air quality is rated Good with a median AQI of 35. The city sits at an elevation of 2,382 feet.

Temperature

26°F Jan (-4°C) 77°F Jul (25°C)

Annual Average	50.4°F
	7% below US avg
January Average	26°F (-4°C)
July Average	77°F (25°C)
Sunny Days	302 days/yr

Geography

Elevation	2,382 ft (726 m)
Area	1.3 sq mi (3.5 km²)
Population Density	40/sq mi
Coordinates	43.7273°N, 101.9833°W
Timezone	America/Chicago
County	Jackson County County
Nearest Airport	Rapid City Regional (RAP) 58 miles away

Precipitation & Snow

Annual Rainfall 19.6"

48% below US avg

Snowfall 38.0"

Wettest Month (Jun) 3.03"

Driest Month (Jan) 0.31"

Air Quality

AQI Median	35.0
Rating	Good

Natural Hazard Risk

Overall Risk	Very Low
Risk Score	10.2 / 100
Social Vulnerability	99.7 / 100
Community Resilience	0.4 / 100

Hazard Breakdown

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

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

Earthquake History

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

May 25, 2003	10 km SSW of Martin, South Dakota	M4.0	73 km	5 km
Jan 28, 1990	8 km N of Manderson-White Horse Creek, South Dakota	M4.0	62 km	5 km
Feb 6, 1996	13 km WNW of Hill City, South Dakota	M3.7	143 km	5 km
Mar 9, 2025	7 km W of Fairburn, South Dakota	M3.6	106 km	5 km
Dec 12, 2013	10 km WSW of Hermosa, South Dakota	M3.5	108 km	5 km
Mar 26, 2021	10 km E of Edgemont, South Dakota	M3.4	146 km	5 km
Aug 9, 2011	2 km S of Fort Pierre, South Dakota	M3.3	145 km	5 km
Aug 5, 2022	4 km ENE of Draper, South Dakota	M3.2	122 km	9 km
Mar 2, 1990	7 km N of Manderson-White Horse Creek, South Dakota	M3.2	63 km	5 km
Jul 12, 1998	7 km E of Corn Creek, South Dakota	M3.1	73 km	5 km
Feb 20, 1993	21 km WSW of Cody, Nebraska	M3.1	108 km	5 km
Feb 7, 2007	11 km WSW of Wasta, South Dakota	M3.1	59 km	5 km
Jun 18, 1998	23 km S of Chadron, Nebraska	M3.1	148 km	5 km
Jan 16, 2012	25 km E of Buffalo Gap, South Dakota	M3.0	86 km	5 km
Jun 16, 2024	7 km NNE of Buffalo Gap, South Dakota	M2.9	105 km	8 km
Apr 4, 2024	19 km SW of Interior, South Dakota	M2.8	19 km	9 km
Jul 17, 2016	15 km NNE of Oelrichs, South Dakota	M2.8	106 km	5 km
Mar 18, 1994	4 km SSW of Hot Springs, South Dakota	M2.8	128 km	5 km
Apr 24, 2007	23 km WSW of Hay Springs, Nebraska	M2.7	149 km	5 km
Jun 8, 2025	19 km NW of Wasta, South Dakota	M2.6	72 km	5 km

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

Tornado History

173 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF3. Total: 14 injuries.

Date	Rating	Distance	Path	Fatalities
Jun 6, 1963	EF3	67 km	24.4 mi	0
Aug 6, 1956	EF3	38 km	28.3 mi	0
Jun 12, 2022	EF2	95 km	3.9 mi	0
Jun 12, 2022	EF2	86 km	0.5 mi	0
May 24, 2010	EF2	90 km	22.3 mi	0
Jul 3, 2003	EF2	65 km	3.0 mi	0
Jun 4, 1999	EF2	89 km	4.0 mi	0
Jun 7, 1994	EF2	58 km	10.0 mi	0
Jun 15, 1992	EF2	42 km	2.0 mi	0
Mar 29, 1982	EF2	62 km	0.2 mi	0
Jun 25, 1978	EF2	91 km	11.1 mi	0
Jul 10, 1977	EF2	95 km	15.9 mi	0
May 19, 1974	EF2	80 km	2.7 mi	0
Jul 26, 1964	EF2	47 km	0.1 mi	0
May 2, 1964	EF2	25 km	14.8 mi	0
Aug 31, 1959	EF2	77 km	0.1 mi	0
Jun 14, 1953	EF2	48 km	27.7 mi	0
Jun 29, 2019	EF1	54 km	5.8 mi	0
Jul 6, 2016	EF1	92 km	1.1 mi	0
May 28, 2013	EF1	51 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: WELLNITZ (77,277 acres, 2012).

Year	Name	Acres Burned	Distance
2012	WELLNITZ	77,277	100 km
2016	COTTONWOOD CA	41,775	22 km
2012	LONGHORN COMPLEX	41,443	95 km
2007	STAMPEDE	22,848	90 km
2006	WHITE OWL	20,022	100 km
1985	YELLOWBEAR	19,212	45 km
2016	FREEMAN	19,121	89 km
1988	LIGHTNING	18,426	94 km
1985	4TH OFJULY	18,177	90 km
2012	HAY CANYON	17,815	94 km
2024	POWER DAM ROAD	15,047	94 km
2000	HASNOHORSE	13,420	82 km
2022	CASINO	11,583	99 km
1987	GRASS CK3	11,125	71 km
2000	DECKER	10,883	50 km
2000	PEPPER CREEK	8,915	76 km
2021	DRY CREEK CA	8,123	92 km
2002	WANNA	7,699	83 km
2002	COTTONWOOD	6,696	51 km
1985	CALICO	6,475	83 km

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

Monthly Weather

Month	Avg Temperature	Precipitation	Summary
January	26°F (-4°C)	0.3 in	Driest
February	28°F (-2°C)	0.4 in
March	36°F (2°C)	1.1 in
April	47°F (8°C)	1.8 in
May	58°F (15°C)	2.8 in
June	68°F (20°C)	3.0 in	Wettest
July	77°F (25°C)	2.4 in	Warmest
August	74°F (23°C)	1.6 in
September	63°F (17°C)	1.2 in
October	50°F (10°C)	1.3 in
November	34°F (1°C)	0.6 in
December	25°F (-4°C)	0.4 in	Coldest

Interior has a seasonal temperature swing of 52°F / from 25°F in December to 77°F in July. Total annual precipitation is 16.9 inches, with June being the wettest month (3.0") and January the driest (0.3").

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