Weather & Climate in Brant Lake South, SD
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Brant Lake South experiences four distinct seasons with an average annual temperature of 46°F (8°C). Winters average 16°F in January while summers reach 72°F in July. Annual precipitation totals 27.4 inches (drier than the 38-inch national average). The area receives 42.5 inches of snow annually, making winter weather a significant factor for residents. Air quality is rated Good with a median AQI of 34. 81% of days have good air quality. The city sits at an elevation of 1,623 feet.
Temperature
16°F Jan (-9°C)
72°F Jul (22°C)
| Annual Average | 45.9°F |
| 15% below US avg | |
| January Average | 16°F (-9°C) |
| July Average | 72°F (22°C) |
Geography
| Elevation | 1,623 ft (495 m) |
| Area | 2.7 sq mi (7.1 km²) |
| Population Density | 396/sq mi |
| Coordinates | 43.9109°N, 96.9408°W |
| Timezone | America/Chicago |
| County | Minnehaha County County |
| Nearest Airport | Joe Foss Field (FSD) 25 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 34.0 |
| Rating | Good |
| Good Days % | 81.4% |
| Unhealthy Days | 2 |
Natural Hazard Risk
| Overall Risk | Relatively Moderate |
| Risk Score | 89.5 / 100 |
| Social Vulnerability | 14.1 / 100 |
| Community Resilience | 86.9 / 100 |
Hazard Breakdown
| Tornado | Relatively High |
| Earthquake | Very Low |
| Wildfire | Relatively Low |
| Flood | Relatively Moderate |
| Hail | Relatively Moderate |
| Strong Wind | Relatively High |
| Heat Wave | Relatively Moderate |
| Winter Weather | Relatively High |
| Lightning | Relatively Low |
| Ice Storm | Very High |
| Drought | Relatively Moderate |
| Cold Wave | Relatively High |
| Landslide | Very Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
5 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M3.6.
| Oct 25, 1990 | 8 km N of Plankinton, South Dakota | M3.6 | 124 km | 5 km |
| Jul 26, 2002 | 0 km WSW of Huron, South Dakota | M3.1 | 114 km | 5 km |
| Jan 4, 2021 | 5 km N of Tyndall, South Dakota | M3.1 | 122 km | 5 km |
| Jan 16, 2022 | 9 km NE of Plankinton, South Dakota | M2.5 | 118 km | 5 km |
| Mar 6, 2024 | 6 km SSE of Santee, Nebraska | M2.5 | 143 km | 5 km |
Source: USGS Earthquake Catalog (M2.5+, 1990-2025). Sorted by magnitude.
Tornado History
601 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF5. Total: 21 fatalities, 466 injuries.
| Date | Rating | Distance | Path | Fatalities |
| Jun 16, 1992 | EF5 | 75 km | 16.0 mi | 1 |
| Jun 13, 1968 | EF5 | 99 km | 9.1 mi | 9 |
| Jun 25, 2010 | EF4 | 95 km | 13.7 mi | 0 |
| Jun 24, 2003 | EF4 | 78 km | 10.0 mi | 0 |
| May 30, 1998 | EF4 | 62 km | 14.0 mi | 6 |
| Jun 7, 1993 | EF4 | 27 km | 10.0 mi | 0 |
| Jun 7, 1993 | EF4 | 21 km | 54.0 mi | 0 |
| Jun 16, 1992 | EF4 | 84 km | 7.0 mi | 0 |
| Jun 7, 1965 | EF4 | 86 km | 7.8 mi | 1 |
| Jul 7, 1955 | EF4 | 87 km | 30.0 mi | 1 |
| May 30, 2022 | EF3 | 99 km | 13.3 mi | 0 |
| Jun 7, 1993 | EF3 | 10 km | 6.0 mi | 0 |
| Jun 7, 1993 | EF3 | 30 km | 5.0 mi | 0 |
| Jun 7, 1993 | EF3 | 4 km | 6.0 mi | 0 |
| May 7, 1993 | EF3 | 45 km | 10.0 mi | 0 |
| Jun 16, 1992 | EF3 | 51 km | 3.0 mi | 0 |
| Jun 16, 1992 | EF3 | 92 km | 12.0 mi | 0 |
| Jun 16, 1992 | EF3 | 52 km | 4.0 mi | 0 |
| Apr 20, 1985 | EF3 | 67 km | 8.0 mi | 0 |
| Aug 3, 1981 | EF3 | 72 km | 12.8 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950-2024, US only).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 16°F (-9°C) | 0.5 in | Coldest, Driest |
| February | 21°F (-6°C) | 0.9 in | |
| March | 33°F (0°C) | 1.3 in | |
| April | 46°F (8°C) | 2.9 in | |
| May | 58°F (15°C) | 4.0 in | Wettest |
| June | 68°F (20°C) | 3.9 in | |
| July | 72°F (22°C) | 3.2 in | Warmest |
| August | 70°F (21°C) | 3.4 in | |
| September | 63°F (17°C) | 3.1 in | |
| October | 49°F (9°C) | 2.1 in | |
| November | 34°F (1°C) | 1.0 in | |
| December | 21°F (-6°C) | 1.1 in |
Brant Lake South has a seasonal temperature swing of 56°F / from 16°F in January to 72°F in July. Total annual precipitation is 27.4 inches, with May being the wettest month (4.0") and January the driest (0.5").