Weather & Climate in Iroquois, SD
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Iroquois experiences four distinct seasons with an average annual temperature of 46°F (8°C). Winters average 16°F in January while summers reach 74°F in July. Annual precipitation totals 23.1 inches (drier than the 38-inch national average). The area receives 39.0 inches of snow annually, a moderate snowfall amount. The city sits at an elevation of 1,395 feet.
Temperature
16°F Jan (-9°C)
74°F Jul (23°C)
| Annual Average | 45.9°F |
| 15% below US avg | |
| January Average | 16°F (-9°C) |
| July Average | 74°F (23°C) |
Geography
| Elevation | 1,395 ft (425 m) |
| Area | 0.6 sq mi (1.6 km²) |
| Population Density | 685/sq mi |
| Coordinates | 44.3679°N, 97.8495°W |
| Timezone | America/Chicago |
| County | Kingsbury County County |
| Nearest Airport | Huron Regional (HON) 19 miles away |
Precipitation & Snow
Air Quality
Natural Hazard Risk
| Overall Risk | Very Low |
| Risk Score | 7.9 / 100 |
| Social Vulnerability | 10.6 / 100 |
| Community Resilience | 89.1 / 100 |
Hazard Breakdown
| Tornado | Relatively Low |
| Earthquake | Very Low |
| Wildfire | Very Low |
| Flood | Very Low |
| Hail | Relatively Low |
| Strong Wind | Relatively Low |
| Heat Wave | Very Low |
| Winter Weather | Relatively Low |
| 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
6 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 | 81 km | 5 km |
| Jul 26, 2002 | 0 km WSW of Huron, South Dakota | M3.1 | 29 km | 5 km |
| Jan 4, 2021 | 5 km N of Tyndall, South Dakota | M3.1 | 147 km | 5 km |
| Feb 7, 2014 | 11 km NE of Bijou Hills, South Dakota | M3.0 | 130 km | 5 km |
| Jul 3, 1995 | 9 km SSW of Fort Thompson, South Dakota | M2.8 | 138 km | 5 km |
| Jan 16, 2022 | 9 km NE of Plankinton, South Dakota | M2.5 | 80 km | 5 km |
Source: USGS Earthquake Catalog (M2.5+, 1990-2025). Sorted by magnitude.
Tornado History
474 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF4. Total: 8 fatalities, 234 injuries.
| Date | Rating | Distance | Path | Fatalities |
| Jun 18, 2014 | EF4 | 57 km | 11.5 mi | 0 |
| Jun 24, 2003 | EF4 | 12 km | 10.0 mi | 0 |
| May 30, 1998 | EF4 | 70 km | 14.0 mi | 6 |
| Jun 7, 1993 | EF4 | 71 km | 10.0 mi | 0 |
| May 30, 2022 | EF3 | 94 km | 13.3 mi | 0 |
| May 5, 2007 | EF3 | 89 km | 4.0 mi | 0 |
| Aug 24, 2006 | EF3 | 74 km | 24.5 mi | 0 |
| Jun 24, 2003 | EF3 | 56 km | 6.0 mi | 0 |
| Jun 24, 2003 | EF3 | 14 km | 3.5 mi | 0 |
| Jun 7, 1993 | EF3 | 69 km | 5.0 mi | 0 |
| Jun 7, 1993 | EF3 | 89 km | 6.0 mi | 0 |
| Jun 7, 1993 | EF3 | 78 km | 5.0 mi | 0 |
| Jun 7, 1993 | EF3 | 81 km | 6.0 mi | 0 |
| May 7, 1993 | EF3 | 96 km | 10.0 mi | 0 |
| Jun 16, 1992 | EF3 | 41 km | 3.0 mi | 0 |
| Jun 16, 1992 | EF3 | 54 km | 4.0 mi | 0 |
| May 12, 1984 | EF3 | 58 km | 27.0 mi | 0 |
| Jul 18, 1983 | EF3 | 80 km | 0.5 mi | 0 |
| Jun 15, 1970 | EF3 | 76 km | 0.1 mi | 0 |
| Jun 20, 1968 | EF3 | 77 km | 9.9 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950-2024, US only).
Wildfire History
2 wildfires (100+ acres) recorded within 100 km. Largest: GANN VALLEY (2,534 acres, 2000).
| Year | Name | Acres Burned | Distance |
| 2000 | GANN VALLEY | 2,534 | 87 km |
| 2009 | TAHOHPI WUI RX | 1,166 | 43 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 16°F (-9°C) | 0.5 in | Coldest, Driest |
| February | 21°F (-6°C) | 0.7 in | |
| March | 33°F (0°C) | 1.1 in | |
| April | 46°F (8°C) | 2.3 in | |
| May | 58°F (14°C) | 2.9 in | |
| June | 68°F (20°C) | 3.7 in | Wettest |
| July | 74°F (23°C) | 3.3 in | Warmest |
| August | 71°F (22°C) | 2.9 in | |
| September | 63°F (17°C) | 2.4 in | |
| October | 48°F (9°C) | 1.9 in | |
| November | 33°F (1°C) | 0.8 in | |
| December | 21°F (-6°C) | 0.7 in |
Iroquois has a seasonal temperature swing of 58°F / from 16°F in January to 74°F in July. Total annual precipitation is 23.2 inches, with June being the wettest month (3.7") and January the driest (0.5").