Third Lake, IL
Full City Profile · Illinois · McHenry County County
5.0
/5.0
A+
Excellent
1,203
Population
2,039/sq mi density
$150,893
Median Income
$68,252 per capita
$329,500
Home Value
$428,031 Zillow
48°F
Avg Temperature
A+
Overall
5.0 / 5.0
Strong
A+
Economy
4.9 / 5.0
$150,893 median income, 2.8% unemployment
A+
Affordability
5.0 / 5.0
$329,500 home value, /mo rent
A+
Education
5.0 / 5.0
70.9% bachelor's degree or higher
Third Lake experiences four distinct seasons with an average annual temperature of 48°F (9°C). Winters average 23°F in January while summers reach 72°F in July. Annual precipitation totals 36.4 inches. The area receives 43.4 inches of snow annually. Air quality is rated Good with a median AQI of 43.
Temperature
23°F Jan (-5°C)
72°F Jul (22°C)
| Annual Average | 48.3°F |
| 11% below US avg | |
| January Average | 23°F (-5°C) |
| July Average | 72°F (22°C) |
Geography
| Elevation | 766 ft (233 m) |
| Area | 0.6 sq mi (1.5 km²) |
| Population Density | 2,039/sq mi |
| Coordinates | 42.3698°N, 88.0091°W |
| Timezone | America/Chicago |
| County | McHenry County County |
| Nearest Airport | Kenosha Regional (ENW) 16 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 43.0 |
| Rating | Good |
| Good Days % | 66.9% |
| Unhealthy Days | 1 |
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 | 119 km |
Source: NOAA/NCEI Historical Tsunami Database. Sorted by wave height.
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 23°F (-5°C) | 2.2 in | Coldest |
| February | 26°F (-3°C) | 1.9 in | |
| March | 36°F (2°C) | 2.4 in | |
| April | 46°F (8°C) | 3.7 in | |
| May | 56°F (14°C) | 4.1 in | |
| June | 66°F (19°C) | 4.1 in | Wettest |
| July | 72°F (22°C) | 3.9 in | Warmest |
| August | 71°F (21°C) | 3.4 in | |
| September | 63°F (17°C) | 3.3 in | |
| October | 52°F (11°C) | 3.1 in | |
| November | 40°F (4°C) | 2.4 in | |
| December | 29°F (-2°C) | 1.9 in | Driest |
Third Lake has a seasonal temperature swing of 48°F / from 23°F in January to 72°F in July. Total annual precipitation is 36.4 inches, with June being the wettest month (4.1") and December the driest (1.9").