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Mount Vernon, IL
Full City Profile · Illinois · Jefferson County County
2.9
/5.0
C+
Fair
14,492
Population
989/sq mi density
$52,751
Median Income
$29,722 per capita
$89,700
Home Value
$129,300 Zillow
$893
Median Rent
26.1% income on rent
55°F
Avg Temperature
293 sunny days/yr
1,446
Violent Crime/100K
4,939 property/100K
C+
Overall
2.9 / 5.0
Fair overall score based on economy, affordability, safety and education
B
Economy
3.1 / 5.0
$52,751 median income, 5.1% unemployment
A+
Affordability
5.0 / 5.0
$89,700 home value, $893/mo rent
F
Safety
1.0 / 5.0
1,446 violent crimes/100K (280% above avg)
C+
Education
2.5 / 5.0
19.0% bachelor's degree or higher
Mount Vernon experiences four distinct seasons with an average annual temperature of 55°F (13°C). Winters average 30°F in January while summers reach 77°F in July. The area gets 293 sunny days per year. Annual precipitation totals 45.0 inches. The area receives 10.4 inches of snow annually. Air quality is rated Good with a median AQI of 43.
Temperature
30°F Jan (-1°C)
77°F Jul (25°C)
| Annual Average | 54.5°F |
| 1% above US avg | |
| January Average | 30°F (-1°C) |
| July Average | 77°F (25°C) |
| Sunny Days | 293 days/yr |
Geography
| Elevation | 523 ft (159 m) |
| Area | 13.2 sq mi (34.1 km²) |
| Population Density | 989/sq mi |
| Coordinates | 38.3142°N, 88.9175°W |
| Timezone | America/Chicago |
| County | Jefferson County County |
| Nearest Airport | St Louis Regional (ALN) 73 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 43.0 |
| Rating | Good |
Natural Hazard Risk
| Overall Risk | Relatively Low |
| Risk Score | 77.2 / 100 |
| Social Vulnerability | 52.8 / 100 |
| Community Resilience | 79.1 / 100 |
Hazard Breakdown
| Tornado | Relatively Moderate |
| Hurricane | Very Low |
| Earthquake | Relatively Moderate |
| Wildfire | Very Low |
| Flood | Relatively Low |
| Hail | Relatively Moderate |
| Strong Wind | Relatively High |
| Heat Wave | Relatively Moderate |
| Winter Weather | Relatively High |
| Lightning | Relatively Low |
| Ice Storm | Relatively Low |
| Drought | Relatively Low |
| Cold Wave | Relatively Low |
| Landslide | Relatively Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 30°F (-1°C) | 2.4 in | Coldest, Driest |
| February | 34°F (1°C) | 2.6 in | |
| March | 45°F (7°C) | 4.2 in | |
| April | 55°F (13°C) | 4.2 in | |
| May | 65°F (18°C) | 4.5 in | Wettest |
| June | 74°F (23°C) | 3.8 in | |
| July | 77°F (25°C) | 3.6 in | Warmest |
| August | 76°F (24°C) | 3.2 in | |
| September | 69°F (21°C) | 3.1 in | |
| October | 57°F (14°C) | 3.0 in | |
| November | 46°F (8°C) | 4.1 in | |
| December | 35°F (2°C) | 3.4 in |
Mount Vernon has a seasonal temperature swing of 46°F / from 30°F in January to 77°F in July. Total annual precipitation is 42.1 inches, with May being the wettest month (4.5") and January the driest (2.4").