Johnsburg, IL
Full City Profile · Illinois · McHenry County County
4.4
/5.0
A
Great
6,374
Population
879/sq mi density
$106,827
Median Income
$49,584 per capita
$312,200
Home Value
$409,057 Zillow
$1,330
Median Rent
30.1% income on rent
49°F
Avg Temperature
A
Overall
4.4 / 5.0
Strong
A+
Economy
4.8 / 5.0
$106,827 median income, 2.2% unemployment
A+
Affordability
5.0 / 5.0
$312,200 home value, $1,330/mo rent
B
Education
3.4 / 5.0
30.6% bachelor's degree or higher
Johnsburg 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. 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) |
Geography
| Elevation | 811 ft (247 m) |
| Area | 7.3 sq mi (18.8 km²) |
| Population Density | 879/sq mi |
| Coordinates | 42.3832°N, 88.2468°W |
| Timezone | America/Chicago |
| County | McHenry County County |
| Nearest Airport | Kenosha Regional (ENW) 22 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 | 136 km |
Source: NOAA/NCEI Historical Tsunami Database. Sorted by wave height.
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 22°F (-6°C) | 1.7 in | Coldest |
| February | 25°F (-4°C) | 1.6 in | Driest |
| March | 36°F (2°C) | 2.2 in | |
| April | 48°F (9°C) | 3.6 in | |
| May | 59°F (15°C) | 4.5 in | |
| June | 69°F (20°C) | 4.8 in | Wettest |
| July | 73°F (23°C) | 3.8 in | Warmest |
| August | 71°F (22°C) | 3.7 in | |
| September | 64°F (18°C) | 3.6 in | |
| October | 51°F (11°C) | 3.2 in | |
| November | 39°F (4°C) | 2.4 in | |
| December | 28°F (-2°C) | 1.9 in |
Johnsburg has a seasonal temperature swing of 51°F / from 22°F in January to 73°F in July. Total annual precipitation is 37.0 inches, with June being the wettest month (4.8") and February the driest (1.6").