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Weather & Climate in Westport, SD
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Westport has a cool climate with an average annual temperature of 43°F (6°C). Winters average 11°F in January while summers reach 72°F in July / a wide seasonal temperature swing of 61°F. The area gets 276 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 22.5 inches (drier than the 38-inch national average). The area receives 37.8 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 1,334 feet.
Temperature
11°F Jan (-12°C)
72°F Jul (22°C)
| Annual Average | 42.8°F |
| 21% below US avg | |
| January Average | 11°F (-12°C) |
| July Average | 72°F (22°C) |
| Sunny Days | 276 days/yr |
Geography
| Elevation | 1,334 ft (407 m) |
| Area | 0.2 sq mi (0.6 km²) |
| Population Density | 388/sq mi |
| Coordinates | 45.6478°N, 98.4981°W |
| Timezone | America/Chicago |
| County | Brown County County |
| Nearest Airport | Aberdeen Regional (ABR) 14 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 35.0 |
| Rating | Good |
Natural Hazard Risk
| Overall Risk | Relatively Low |
| Risk Score | 73.5 / 100 |
| Social Vulnerability | 24.1 / 100 |
| Community Resilience | 85.6 / 100 |
Hazard Breakdown
| Tornado | Relatively Moderate |
| Earthquake | Very Low |
| Wildfire | Relatively Low |
| Flood | Relatively Low |
| Hail | Relatively Moderate |
| Strong Wind | Relatively Moderate |
| Heat Wave | Relatively Low |
| Winter Weather | Very High |
| Lightning | Very Low |
| Ice Storm | Relatively Moderate |
| Drought | Very Low |
| Cold Wave | Relatively High |
| Landslide | Very Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
3 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M3.7.
| Oct 20, 1995 | 8 km SSE of New Effington, South Dakota | M3.7 | 128 km | 5 km |
| Jul 26, 2002 | 0 km WSW of Huron, South Dakota | M3.1 | 145 km | 5 km |
| Aug 15, 2017 | 8 km E of Agar, South Dakota | M3.0 | 146 km | 5 km |
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Tornado History
356 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF4. Total: 6 fatalities, 63 injuries.
| Date | Rating | Distance | Path | Fatalities |
| May 22, 2010 | EF4 | 100 km | 5.7 mi | 0 |
| Jun 23, 2002 | EF4 | 6 km | 9.0 mi | 0 |
| Jul 17, 2011 | EF3 | 94 km | 16.2 mi | 0 |
| Aug 24, 2006 | EF3 | 92 km | 14.0 mi | 0 |
| Jun 23, 2002 | EF3 | 13 km | 10.0 mi | 0 |
| May 31, 1996 | EF3 | 20 km | 32.0 mi | 0 |
| Aug 19, 1974 | EF3 | 96 km | 0.1 mi | 0 |
| May 20, 1974 | EF3 | 98 km | 17.3 mi | 0 |
| Jul 1, 1973 | EF3 | 70 km | 0.1 mi | 0 |
| Jul 1, 1973 | EF3 | 44 km | 0.3 mi | 1 |
| Jun 25, 1969 | EF3 | 39 km | 1.5 mi | 0 |
| Jul 31, 1966 | EF3 | 85 km | 26.4 mi | 2 |
| May 20, 1965 | EF3 | 30 km | 3.8 mi | 0 |
| Jun 21, 1961 | EF3 | 29 km | 156.3 mi | 1 |
| Jun 9, 1957 | EF3 | 85 km | 1.0 mi | 0 |
| Jul 4, 2020 | EF2 | 23 km | 2.7 mi | 0 |
| Jul 10, 2011 | EF2 | 67 km | 26.0 mi | 0 |
| May 22, 2010 | EF2 | 42 km | 18.6 mi | 0 |
| May 22, 2010 | EF2 | 28 km | 1.3 mi | 0 |
| Jun 29, 2005 | EF2 | 76 km | 8.0 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950–2024, US only).
Wildfire History
7 wildfires (100+ acres) recorded within 100 km. Largest: ROHRBACH (2,887 acres, 2022).
| Year | Name | Acres Burned | Distance |
| 2022 | ROHRBACH | 2,887 | 83 km |
| 2003 | JOEL BERTSCH 2 | 1,460 | 81 km |
| 2004 | TACOMA PARK PLACE | 1,336 | 23 km |
| 2004 | ALLEN STUECKLE | 1,330 | 93 km |
| 2016 | SLR 2016 RX MICHELL | 1,242 | 36 km |
| 2000 | PHEASANT OPENER | 1,206 | 60 km |
| 1992 | SPRING LK | 1,001 | 96 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 11°F (-12°C) | 0.5 in | Coldest |
| February | 18°F (-8°C) | 0.5 in | |
| March | 30°F (-1°C) | 1.3 in | |
| April | 45°F (7°C) | 2.0 in | |
| May | 58°F (14°C) | 2.6 in | |
| June | 67°F (19°C) | 3.4 in | Wettest |
| July | 72°F (22°C) | 2.8 in | Warmest |
| August | 70°F (21°C) | 2.3 in | |
| September | 60°F (15°C) | 1.9 in | |
| October | 47°F (8°C) | 1.5 in | |
| November | 29°F (-2°C) | 0.7 in | |
| December | 15°F (-9°C) | 0.4 in | Driest |
Westport has a seasonal temperature swing of 61°F / from 11°F in January to 72°F in July. Total annual precipitation is 19.8 inches, with June being the wettest month (3.4") and December the driest (0.4").