All Countries
Grassland Colony, SD
Full City Profile · South Dakota · Brown County County
36
Population
84/sq mi density
42°F
Avg Temperature
276 sunny days/yr
Grassland Colony has a cool climate with an average annual temperature of 42°F (6°C). Winters average 11°F in January while summers reach 71°F in July. The area gets 276 sunny days per year. Annual precipitation totals 21.8 inches. Air quality is rated Good with a median AQI of 35.
Temperature
11°F Jan (-12°C)
71°F Jul (22°C)
| Annual Average | 42.2°F |
| 22% below US avg | |
| January Average | 11°F (-12°C) |
| July Average | 71°F (22°C) |
| Sunny Days | 276 days/yr |
Geography
| Elevation | 1,487 ft (453 m) |
| Area | 0.4 sq mi (1.1 km²) |
| Population Density | 84/sq mi |
| Coordinates | 45.6682°N, 98.7965°W |
| Timezone | America/Chicago |
| County | Brown County County |
| Nearest Airport | Aberdeen Regional (ABR) 24 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 35.0 |
| Rating | Good |
Air Pollutants (EPA 2023)
| PM2.5 (Fine Particles) | 7.1 μg/m³ |
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)
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 11°F (-12°C) | 0.5 in | Coldest |
| February | 17°F (-8°C) | 0.5 in | |
| March | 29°F (-2°C) | 1.3 in | |
| April | 44°F (7°C) | 2.2 in | |
| May | 57°F (14°C) | 2.7 in | |
| June | 66°F (19°C) | 3.4 in | Wettest |
| July | 71°F (22°C) | 2.6 in | Warmest |
| August | 70°F (21°C) | 2.1 in | |
| September | 59°F (15°C) | 1.8 in | |
| October | 46°F (8°C) | 1.2 in | |
| November | 28°F (-2°C) | 0.7 in | |
| December | 15°F (-9°C) | 0.4 in | Driest |
Grassland Colony has a seasonal temperature swing of 60°F / from 11°F in January to 71°F in July. Total annual precipitation is 19.3 inches, with June being the wettest month (3.4") and December the driest (0.4").