Sinai, SD

Full City Profile · South Dakota · Lake County County

3.0 /5.0

B Good

220 Population 595/sq mi density

$52,188 Median Income $24,065 per capita

$91,500 Home Value $323,488 Zillow

45°F Avg Temperature 276 sunny days/yr

142 Violent Crime/100K 1,332 property/100K

Overall

3.0 / 5.0

Good overall score based on economy, affordability, safety and education

Economy

3.4 / 5.0

$52,188 median income, 6.3% unemployment

A+

Affordability

5.0 / 5.0

$91,500 home value, /mo rent

Safety

1.0 / 5.0

142 violent crimes/100K

C+

Education

2.7 / 5.0

21.3% bachelor's degree or higher

Sinai has a cool climate with an average annual temperature of 45°F (7°C). Winters average 15°F in January while summers reach 72°F in July. The area gets 276 sunny days per year. Annual precipitation totals 26.2 inches. Air quality is rated Good with a median AQI of 35.

Temperature

15°F Jan (-10°C) 72°F Jul (22°C)

Annual Average	44.7°F
	17% below US avg
January Average	15°F (-10°C)
July Average	72°F (22°C)
Sunny Days	276 days/yr

Geography

Elevation	1,777 ft (542 m)
Area	0.4 sq mi (1.0 km²)
Population Density	595/sq mi
Coordinates	44.2445°N, 97.0440°W
Timezone	America/Chicago
County	Lake County County
Nearest Airport	Brookings Regional (BKX) 12 miles away

Precipitation & Snow

Annual Rainfall 26.2"

31% below US avg

Wettest Month (Jun) 3.98"

Driest Month (Jan) 0.47"

Air Quality

AQI Median	35.0
Rating	Good

Natural Hazard Risk

Overall Risk	Very Low
Risk Score	32.6 / 100
Social Vulnerability	25.9 / 100
Community Resilience	74.2 / 100

Hazard Breakdown

Tornado	Relatively Moderate
Earthquake	Very Low
Wildfire	Very 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

4 earthquakes (M2.5+) within 150 km since 1990. Strongest: M3.6. Most recent: M2.5 on Jan 16, 2022.

Oct 25, 1990	8 km N of Plankinton, South Dakota	M3.6	125 km
Jul 26, 2002	0 km WSW of Huron, South Dakota	M3.1	94 km
Jan 4, 2021	5 km N of Tyndall, South Dakota	M3.1	149 km
Jan 16, 2022	9 km NE of Plankinton, South Dakota	M2.5	121 km

Source: USGS (M2.5+, 1990–2025)

Tornado History

530 tornadoes (EF0+) within 100 km since 1950. Strongest: EF5. Total: 8 fatalities, 298 injuries.

Date	Rating	Distance	Fatalities
Jun 16, 1992	EF5	96 km	1
Jun 24, 2003	EF4	58 km	0
May 30, 1998	EF4	75 km	6
Jun 7, 1993	EF4	45 km	0
Jun 7, 1993	EF4	59 km	0
Jun 16, 1992	EF4	97 km	0
Jul 7, 1955	EF4	72 km	1
May 30, 2022	EF3	64 km	0
Jun 24, 2003	EF3	80 km	0
Jun 7, 1993	EF3	53 km	0
Jun 7, 1993	EF3	28 km	0
Jun 7, 1993	EF3	41 km	0
May 7, 1993	EF3	75 km	0
Jun 16, 1992	EF3	99 km	0
Jun 16, 1992	EF3	15 km	0
Jun 16, 1992	EF3	43 km	0
Apr 20, 1985	EF3	85 km	0
May 12, 1984	EF3	89 km	0
Jul 18, 1983	EF3	74 km	0
Jun 15, 1970	EF3	13 km	0

Source: NOAA SPC (EF0+, 1950–2024)

Monthly Weather

Month	Avg Temperature	Precipitation	Summary
January	15°F (-10°C)	0.5 in	Coldest, Driest
February	19°F (-7°C)	0.6 in
March	31°F (-1°C)	1.6 in
April	45°F (7°C)	2.2 in
May	58°F (14°C)	2.9 in
June	67°F (19°C)	4.0 in	Wettest
July	72°F (22°C)	3.2 in	Warmest
August	69°F (21°C)	2.9 in
September	60°F (15°C)	2.4 in
October	47°F (8°C)	1.8 in
November	30°F (-1°C)	1.0 in
December	17°F (-8°C)	0.6 in

Sinai has a seasonal temperature swing of 57°F / from 15°F in January to 72°F in July. Total annual precipitation is 23.6 inches, with June being the wettest month (4.0") and January the driest (0.5").

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