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Willow Lake, IL
Full City Profile · Illinois · Stephenson County County
3.5
/5.0
B+
Good
838
Population
307/sq mi density
$93,750
Median Income
$50,571 per capita
$154,100
Home Value
$120,745 Zillow
48°F
Avg Temperature
260 sunny days/yr
193
Violent Crime/100K
2,563 property/100K
B+
Overall
3.5 / 5.0
Good overall score based on economy, affordability, safety and education
A+
Economy
4.9 / 5.0
$93,750 median income, 0.0% unemployment
A+
Affordability
5.0 / 5.0
$154,100 home value, /mo rent
F
Safety
1.0 / 5.0
193 violent crimes/100K
C+
Education
2.9 / 5.0
24.2% bachelor's degree or higher
Willow Lake experiences four distinct seasons with an average annual temperature of 48°F (9°C). Winters average 20°F in January while summers reach 72°F in July. The area gets 260 sunny days per year. Annual precipitation totals 38.4 inches. The area receives 34.5 inches of snow annually. Air quality is rated Good with a median AQI of 43.
Temperature
20°F Jan (-7°C)
72°F Jul (22°C)
| Annual Average | 47.7°F |
| 12% below US avg | |
| January Average | 20°F (-7°C) |
| July Average | 72°F (22°C) |
| Sunny Days | 260 days/yr |
Geography
| Elevation | 809 ft (247 m) |
| Area | 2.7 sq mi (7.1 km²) |
| Population Density | 307/sq mi |
| Coordinates | 42.3342°N, 89.6353°W |
| Timezone | America/Chicago |
| County | Stephenson County County |
| Nearest Airport | Chicago/Rockford International (RFD) 29 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 43.0 |
| Rating | Good |
Natural Hazard Risk
| Overall Risk | Relatively Low |
| Risk Score | 73.9 / 100 |
| Social Vulnerability | 56.7 / 100 |
| Community Resilience | 68.6 / 100 |
Hazard Breakdown
| Tornado | Relatively Moderate |
| Hurricane | Very Low |
| Earthquake | Very Low |
| Wildfire | Very Low |
| Flood | Relatively Moderate |
| Hail | Relatively Moderate |
| Strong Wind | Relatively High |
| Heat Wave | Relatively Low |
| Winter Weather | Relatively Low |
| Lightning | Relatively Low |
| Ice Storm | Relatively Moderate |
| Drought | Relatively Moderate |
| Cold Wave | Relatively Moderate |
| Landslide | Very Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 20°F (-7°C) | 1.2 in | Coldest |
| February | 22°F (-6°C) | 1.1 in | Driest |
| March | 34°F (1°C) | 2.3 in | |
| April | 47°F (8°C) | 3.2 in | |
| May | 58°F (15°C) | 3.7 in | |
| June | 68°F (20°C) | 4.1 in | Wettest |
| July | 72°F (22°C) | 3.7 in | Warmest |
| August | 69°F (21°C) | 4.1 in | |
| September | 62°F (16°C) | 3.9 in | |
| October | 50°F (10°C) | 2.6 in | |
| November | 36°F (2°C) | 2.4 in | |
| December | 23°F (-5°C) | 1.8 in |
Willow Lake has a seasonal temperature swing of 53°F / from 20°F in January to 72°F in July. Total annual precipitation is 34.1 inches, with June being the wettest month (4.1") and February the driest (1.1").