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Flat Rock, IL
Full City Profile · Illinois · Lawrence County County
2.9
/5.0
C+
Fair
362
Population
421/sq mi density
$49,881
Median Income
$28,516 per capita
$56,700
Home Value
$106,877 Zillow
56°F
Avg Temperature
293 sunny days/yr
676
Violent Crime/100K
1,653 property/100K
C+
Overall
2.9 / 5.0
Fair overall score based on economy, affordability, safety and education
B+
Economy
3.6 / 5.0
$49,881 median income, 4.2% unemployment
A+
Affordability
5.0 / 5.0
$56,700 home value, /mo rent
F
Safety
1.0 / 5.0
676 violent crimes/100K (78% above avg)
C
Education
2.1 / 5.0
13.4% bachelor's degree or higher
Flat Rock enjoys a temperate climate with an average annual temperature of 56°F (13°C). Winters average 31°F in January while summers reach 77°F in July. The area gets 293 sunny days per year. Annual precipitation totals 41.7 inches. Air quality is rated Good with a median AQI of 43.
Temperature
31°F Jan (-0°C)
77°F Jul (25°C)
| Annual Average | 55.7°F |
| 3% above US avg | |
| January Average | 31°F (-0°C) |
| July Average | 77°F (25°C) |
| Sunny Days | 293 days/yr |
Geography
| Elevation | 500 ft (152 m) |
| Area | 0.9 sq mi (2.2 km²) |
| Population Density | 421/sq mi |
| Coordinates | 38.9037°N, 87.6734°W |
| Timezone | America/Chicago |
| County | Lawrence County County |
| Nearest Airport | Lawrenceville-Vincennes International (LWV) 10 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 43.0 |
| Rating | Good |
Natural Hazard Risk
| Overall Risk | Relatively Low |
| Risk Score | 49.2 / 100 |
| Social Vulnerability | 57.4 / 100 |
| Community Resilience | 47.3 / 100 |
Hazard Breakdown
| Tornado | Relatively Low |
| Hurricane | Very Low |
| Earthquake | Relatively Low |
| Wildfire | Very Low |
| Flood | Relatively Low |
| Hail | Very Low |
| Strong Wind | Relatively Low |
| Heat Wave | Relatively Low |
| Winter Weather | Relatively Low |
| Lightning | Relatively Low |
| Ice Storm | Relatively Low |
| Drought | Relatively Moderate |
| Cold Wave | Relatively Low |
| Landslide | Very Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 31°F (-0°C) | 2.4 in | Coldest, Driest |
| February | 33°F (0°C) | 2.5 in | |
| March | 44°F (6°C) | 3.9 in | |
| April | 54°F (12°C) | 4.1 in | |
| May | 64°F (18°C) | 4.6 in | Wettest |
| June | 73°F (23°C) | 4.0 in | |
| July | 77°F (25°C) | 4.3 in | Warmest |
| August | 75°F (24°C) | 3.7 in | |
| September | 68°F (20°C) | 3.3 in | |
| October | 56°F (13°C) | 3.0 in | |
| November | 45°F (7°C) | 3.9 in | |
| December | 34°F (1°C) | 3.3 in |
Flat Rock has a seasonal temperature swing of 46°F / from 31°F in January to 77°F in July. Total annual precipitation is 42.8 inches, with May being the wettest month (4.6") and January the driest (2.4").