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Island Lake, IL
Full City Profile · Illinois · McHenry County County
3.4
/5.0
B
Good
8,023
Population
2,381/sq mi density
$98,125
Median Income
$40,068 per capita
$241,900
Home Value
$293,448 Zillow
$1,855
Median Rent
30.8% income on rent
49°F
Avg Temperature
260 sunny days/yr
87
Violent Crime/100K
483 property/100K
B
Overall
3.4 / 5.0
Good overall score based on economy, affordability, safety and education
A+
Economy
4.5 / 5.0
$98,125 median income, 4.9% unemployment
A+
Affordability
5.0 / 5.0
$241,900 home value, $1,855/mo rent
F
Safety
1.0 / 5.0
87 violent crimes/100K
B
Education
3.2 / 5.0
27.6% bachelor's degree or higher
Island Lake experiences four distinct seasons with an average annual temperature of 49°F (9°C). Winters average 22°F in January while summers reach 73°F in July. The area gets 260 sunny days per year. Annual precipitation totals 37.0 inches. The area receives 34.5 inches of snow annually. Air quality is rated Good with a median AQI of 43.
Temperature
22°F Jan (-6°C)
73°F Jul (23°C)
| Annual Average | 48.6°F |
| 10% below US avg | |
| January Average | 22°F (-6°C) |
| July Average | 73°F (23°C) |
| Sunny Days | 260 days/yr |
Geography
| Elevation | 754 ft (230 m) |
| Area | 3.4 sq mi (8.7 km²) |
| Population Density | 2,381/sq mi |
| Coordinates | 42.2788°N, 88.2005°W |
| Timezone | America/Chicago |
| County | McHenry County County |
| Nearest Airport | Chicago O'Hare International (ORD) 26 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 43.0 |
| Rating | Good |
Air Pollutants (EPA 2023)
| Ozone (O₃) | 0.0484 ppm |
| PM2.5 (Fine Particles) | 9.1 μg/m³ |
Natural Hazard Risk
| Overall Risk | Relatively Moderate |
| Risk Score | 90.8 / 100 |
| Social Vulnerability | 10.6 / 100 |
| Community Resilience | 84.0 / 100 |
Hazard Breakdown
| Tornado | Relatively High |
| Hurricane | Very Low |
| Earthquake | Relatively Low |
| Wildfire | Very Low |
| Flood | Relatively Moderate |
| Hail | Relatively Moderate |
| Strong Wind | Relatively High |
| Heat Wave | Relatively Low |
| Winter Weather | Relatively Moderate |
| Lightning | Relatively Moderate |
| Ice Storm | Relatively Low |
| Drought | Relatively Low |
| Cold Wave | Relatively High |
| Landslide | Very Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Tsunami History
1 tsunami recorded within 500 km. Highest wave on record: 3.0 m (10 ft).
| Year | Location | Cause | Max Wave | Deaths | Distance |
| 1954 | MICHIGAN CITY, IN (LAKE MICHIGAN) | Avalanche | 3.0 m | 7 | 127 km |
Source: NOAA/NCEI Historical Tsunami Database. Sorted by wave height.
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 22°F (-6°C) | 1.5 in | Coldest |
| February | 25°F (-4°C) | 1.2 in | Driest |
| March | 36°F (2°C) | 2.5 in | |
| April | 47°F (8°C) | 3.6 in | |
| May | 58°F (15°C) | 3.5 in | |
| June | 68°F (20°C) | 4.1 in | |
| July | 73°F (23°C) | 4.1 in | Warmest |
| August | 71°F (21°C) | 4.1 in | Wettest |
| September | 63°F (17°C) | 3.9 in | |
| October | 51°F (11°C) | 2.4 in | |
| November | 38°F (3°C) | 2.8 in | |
| December | 26°F (-4°C) | 2.1 in |
Island Lake has a seasonal temperature swing of 51°F / from 22°F in January to 73°F in July. Total annual precipitation is 35.7 inches, with August being the wettest month (4.1") and February the driest (1.2").