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Frankfort, IL
Full City Profile · Illinois · Will County County
4.0
/5.0
A
Great
20,417
Population
1,307/sq mi density
$153,714
Median Income
$59,421 per capita
$461,600
Home Value
$480,767 Zillow
$2,175
Median Rent
28.4% income on rent
51°F
Avg Temperature
275 sunny days/yr
83
Violent Crime/100K
1,095 property/100K
A
Overall
4.0 / 5.0
Strong
A+
Economy
4.9 / 5.0
$153,714 median income, 2.4% unemployment
A+
Affordability
5.0 / 5.0
$461,600 home value, $2,175/mo rent
F
Safety
1.0 / 5.0
83 violent crimes/100K
A+
Education
5.0 / 5.0
59.2% bachelor's degree or higher
Frankfort experiences four distinct seasons with an average annual temperature of 51°F (11°C). Winters average 24°F in January while summers reach 77°F in July. The area gets 275 sunny days per year. Annual precipitation totals 41.4 inches. Air quality is rated Good with a median AQI of 43.
Temperature
24°F Jan (-5°C)
77°F Jul (25°C)
| Annual Average | 51.4°F |
| 5% below US avg | |
| January Average | 24°F (-5°C) |
| July Average | 77°F (25°C) |
| Sunny Days | 275 days/yr |
Geography
| Elevation | 719 ft (219 m) |
| Area | 15.6 sq mi (40.5 km²) |
| Population Density | 1,307/sq mi |
| Coordinates | 41.5070°N, 87.8710°W |
| Timezone | America/Chicago |
| County | Will County County |
| Nearest Airport | Joliet Regional (JOT) 16 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 43.0 |
| Rating | Good |
Air Pollutants (EPA 2023)
| Ozone (O₃) | 0.0479 ppm |
| PM2.5 (Fine Particles) | 9.5 μg/m³ |
Natural Hazard Risk
| Overall Risk | Relatively High |
| Risk Score | 97.3 / 100 |
| Social Vulnerability | 13.4 / 100 |
| Community Resilience | 92.4 / 100 |
Hazard Breakdown
| Tornado | Very High |
| Hurricane | Very Low |
| Earthquake | Relatively Moderate |
| Wildfire | Very Low |
| Flood | Relatively High |
| Hail | Relatively Low |
| Strong Wind | Relatively Low |
| Heat Wave | Relatively Moderate |
| Winter Weather | Relatively High |
| Lightning | Relatively High |
| Ice Storm | Relatively Moderate |
| Drought | Relatively Low |
| Cold Wave | Very 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 | 85 km |
Source: NOAA/NCEI Historical Tsunami Database. Sorted by wave height.
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 24°F (-5°C) | 1.6 in | Coldest |
| February | 27°F (-3°C) | 1.5 in | Driest |
| March | 37°F (3°C) | 2.7 in | |
| April | 49°F (9°C) | 3.9 in | |
| May | 60°F (15°C) | 3.9 in | |
| June | 69°F (21°C) | 4.1 in | Wettest |
| July | 77°F (25°C) | 3.9 in | Warmest |
| August | 72°F (22°C) | 3.9 in | |
| September | 64°F (18°C) | 3.6 in | |
| October | 52°F (11°C) | 2.8 in | |
| November | 40°F (4°C) | 3.1 in | |
| December | 28°F (-3°C) | 2.5 in |
Frankfort has a seasonal temperature swing of 53°F / from 24°F in January to 77°F in July. Total annual precipitation is 37.5 inches, with June being the wettest month (4.1") and February the driest (1.5").