All Countries
St. Charles, SD
Full City Profile · South Dakota · Gregory County County
5.0
/5.0
A+
Excellent
11
Population
55/sq mi density
47°F
Avg Temperature
291 sunny days/yr
A+
Overall
5.0 / 5.0
Strong
A+
Education
5.0 / 5.0
0.0% bachelor's degree or higher
St. Charles experiences four distinct seasons with an average annual temperature of 47°F (8°C). Winters average 21°F in January while summers reach 74°F in July. The area gets 291 sunny days per year. Annual precipitation totals 26.7 inches. The area receives 45.0 inches of snow annually. Air quality is rated Good with a median AQI of 35.
Temperature
21°F Jan (-6°C)
74°F Jul (23°C)
| Annual Average | 47.3°F |
| 12% below US avg | |
| January Average | 21°F (-6°C) |
| July Average | 74°F (23°C) |
| Sunny Days | 291 days/yr |
Geography
| Elevation | 2,075 ft (632 m) |
| Area | 0.2 sq mi (0.5 km²) |
| Population Density | 55/sq mi |
| Coordinates | 43.0881°N, 99.0949°W |
| Timezone | America/Chicago |
| County | Gregory County County |
| Nearest Airport | Ainsworth Regional (ANW) 58 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 35.0 |
| Rating | Good |
Natural Hazard Risk
| Overall Risk | Very Low |
| Risk Score | 16.2 / 100 |
| Social Vulnerability | 18.9 / 100 |
| Community Resilience | 78.3 / 100 |
Hazard Breakdown
| Tornado | Relatively Low |
| Earthquake | Very Low |
| Wildfire | Relatively Low |
| Flood | Very Low |
| Hail | Relatively Low |
| Strong Wind | Very Low |
| Heat Wave | Very Low |
| Winter Weather | Relatively Moderate |
| Lightning | Very Low |
| Ice Storm | Relatively Low |
| Drought | Relatively Low |
| Cold Wave | Relatively Moderate |
| Landslide | Very Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 21°F (-6°C) | 0.4 in | Coldest, Driest |
| February | 26°F (-3°C) | 0.6 in | |
| March | 36°F (2°C) | 1.8 in | |
| April | 47°F (9°C) | 2.7 in | |
| May | 59°F (15°C) | 3.9 in | Wettest |
| June | 69°F (20°C) | 3.8 in | |
| July | 74°F (23°C) | 3.3 in | Warmest |
| August | 73°F (23°C) | 2.5 in | |
| September | 63°F (17°C) | 2.6 in | |
| October | 51°F (10°C) | 1.6 in | |
| November | 34°F (1°C) | 0.9 in | |
| December | 24°F (-5°C) | 0.6 in |
St. Charles has a seasonal temperature swing of 53°F / from 21°F in January to 74°F in July. Total annual precipitation is 24.6 inches, with May being the wettest month (3.9") and January the driest (0.4").