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Sumner, IA
Full City Profile · Iowa · Bremer County County
3.3
/5.0
B
Good
2,159
Population
878/sq mi density
$56,174
Median Income
$35,772 per capita
$111,900
Home Value
$136,953 Zillow
$598
Median Rent
23.0% income on rent
46°F
Avg Temperature
260 sunny days/yr
627
Violent Crime/100K
2,281 property/100K
B
Overall
3.3 / 5.0
Good overall score based on economy, affordability, safety and education
A
Economy
4.0 / 5.0
$56,174 median income, 1.6% unemployment
A+
Affordability
5.0 / 5.0
$111,900 home value, $598/mo rent
F
Safety
1.0 / 5.0
627 violent crimes/100K (65% above avg)
B
Education
3.1 / 5.0
26.1% bachelor's degree or higher
Sumner experiences four distinct seasons with an average annual temperature of 46°F (8°C). Winters average 16°F in January while summers reach 72°F in July. The area gets 260 sunny days per year. Annual precipitation totals 38.6 inches. Air quality is rated Good with a median AQI of 43.
Temperature
16°F Jan (-9°C)
72°F Jul (22°C)
| Annual Average | 46.4°F |
| 14% below US avg | |
| January Average | 16°F (-9°C) |
| July Average | 72°F (22°C) |
| Sunny Days | 260 days/yr |
Geography
| Elevation | 1,061 ft (323 m) |
| Area | 2.5 sq mi (6.4 km²) |
| Population Density | 878/sq mi |
| Coordinates | 42.8494°N, 92.0972°W |
| Timezone | America/Chicago |
| County | Bremer County County |
| Nearest Airport | Waterloo Regional (ALO) 25 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 43.0 |
| Rating | Good |
Air Pollutants (EPA 2023)
| Ozone (O₃) | 0.0471 ppm |
Natural Hazard Risk
| Overall Risk | Very Low |
| Risk Score | 24.6 / 100 |
| Social Vulnerability | 10.6 / 100 |
| Community Resilience | 98.0 / 100 |
Hazard Breakdown
| Tornado | Relatively Low |
| Hurricane | Very 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 | Very Low |
| Drought | Relatively Moderate |
| Cold Wave | Relatively Low |
| Landslide | Very Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 16°F (-9°C) | 1.0 in | Coldest, Driest |
| February | 21°F (-6°C) | 1.0 in | |
| March | 33°F (1°C) | 2.2 in | |
| April | 47°F (8°C) | 3.6 in | |
| May | 59°F (15°C) | 4.3 in | |
| June | 68°F (20°C) | 4.5 in | |
| July | 72°F (22°C) | 4.5 in | Warmest |
| August | 69°F (21°C) | 4.7 in | Wettest |
| September | 61°F (16°C) | 3.6 in | |
| October | 50°F (10°C) | 2.6 in | |
| November | 34°F (1°C) | 2.2 in | |
| December | 20°F (-7°C) | 1.4 in |
Sumner has a seasonal temperature swing of 56°F / from 16°F in January to 72°F in July. Total annual precipitation is 35.6 inches, with August being the wettest month (4.7") and January the driest (1.0").