Marvin, SD
Full City Profile · South Dakota · Grant County County
2.6
/5.0
C+
Fair
18
Population
33/sq mi density
$38,750
Median Income
$14,950 per capita
43°F
Avg Temperature
C+
Overall
2.6 / 5.0
Fair overall score based on economy, affordability, safety and education
B
Economy
3.1 / 5.0
$38,750 median income, 0.0% unemployment
C
Education
2.0 / 5.0
12.5% bachelor's degree or higher
Marvin has a cool climate with an average annual temperature of 43°F (6°C). Winters average 11°F in January while summers reach 70°F in July. Annual precipitation totals 25.7 inches. The area receives 58.6 inches of snow annually.
Temperature
11°F Jan (-11°C)
70°F Jul (21°C)
| Annual Average | 42.6°F |
| 21% below US avg | |
| January Average | 11°F (-11°C) |
| July Average | 70°F (21°C) |
Geography
| Elevation | 1,659 ft (506 m) |
| Area | 0.6 sq mi (1.4 km²) |
| Population Density | 33/sq mi |
| Coordinates | 45.2605°N, 96.9154°W |
| Timezone | America/Chicago |
| County | Grant County County |
| Nearest Airport | Watertown Regional (ATY) 27 miles away |
Precipitation & Snow
Air Quality
Natural Hazard Risk
| Overall Risk | Very Low |
| Risk Score | 18.9 / 100 |
| Social Vulnerability | 10.6 / 100 |
| Community Resilience | 78.9 / 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 Moderate |
| Landslide | Very Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 11°F (-11°C) | 0.7 in | Coldest, Driest |
| February | 16°F (-9°C) | 0.7 in | |
| March | 29°F (-2°C) | 1.0 in | |
| April | 43°F (6°C) | 2.3 in | |
| May | 56°F (13°C) | 3.2 in | |
| June | 65°F (19°C) | 4.0 in | |
| July | 70°F (21°C) | 4.1 in | Warmest, Wettest |
| August | 68°F (20°C) | 3.0 in | |
| September | 61°F (16°C) | 2.8 in | |
| October | 46°F (8°C) | 2.5 in | |
| November | 30°F (-1°C) | 0.9 in | |
| December | 17°F (-8°C) | 0.7 in |
Marvin has a seasonal temperature swing of 59°F / from 11°F in January to 70°F in July. Total annual precipitation is 25.7 inches, with July being the wettest month (4.1") and January the driest (0.7").