St. Elmo, IL
Full City Profile · Illinois · Effingham County County
2.7
/5.0
C+
Fair
1,401
Population
947/sq mi density
$47,115
Median Income
$23,540 per capita
$80,300
Home Value
$163,092 Zillow
$759
Median Rent
27.8% income on rent
55°F
Avg Temperature
242
Violent Crime/100K
1,373 property/100K
C+
Overall
2.7 / 5.0
Fair overall score based on economy, affordability, safety and education
B
Economy
3.1 / 5.0
$47,115 median income, 4.5% unemployment
A+
Affordability
5.0 / 5.0
$80,300 home value, $759/mo rent
F
Safety
1.0 / 5.0
242 violent crimes/100K
D
Education
1.7 / 5.0
8.2% bachelor's degree or higher
St. Elmo experiences four distinct seasons with an average annual temperature of 55°F (13°C). Winters average 29°F in January while summers reach 77°F in July. Annual precipitation totals 41.2 inches. The area receives 16.2 inches of snow annually. Air quality is rated Good with a median AQI of 41.
Temperature
29°F Jan (-2°C)
77°F Jul (25°C)
| Annual Average | 54.6°F |
| 1% above US avg | |
| January Average | 29°F (-2°C) |
| July Average | 77°F (25°C) |
Geography
| Elevation | 613 ft (187 m) |
| Area | 0.5 sq mi (1.2 km²) |
| Population Density | 947/sq mi |
| Coordinates | 39.0218°N, 88.8514°W |
| Timezone | America/Chicago |
| County | Effingham County County |
| Nearest Airport | St Louis Regional (ALN) 65 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 41.0 |
| Rating | Good |
| Good Days % | 90.4% |
| Unhealthy Days | 1 |
Air Pollutants (EPA 2023)
| Ozone (O₃) | 0.0488 ppm |
Natural Hazard Risk
| Overall Risk | Relatively Low |
| Risk Score | 53.8 / 100 |
| Social Vulnerability | 23.0 / 100 |
| Community Resilience | 95.0 / 100 |
Hazard Breakdown
| Tornado | Relatively Low |
| Hurricane | Very Low |
| Earthquake | Relatively Low |
| Wildfire | Very Low |
| Flood | Relatively Low |
| Hail | Relatively Low |
| Strong Wind | Relatively Moderate |
| Heat Wave | Relatively Low |
| Winter Weather | Relatively Moderate |
| Lightning | Relatively Low |
| Ice Storm | Relatively Low |
| Drought | Relatively Moderate |
| Cold Wave | Relatively Low |
| Landslide | Relatively Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 29°F (-2°C) | 2.8 in | Coldest |
| February | 34°F (1°C) | 2.4 in | |
| March | 44°F (6°C) | 3.2 in | |
| April | 55°F (13°C) | 4.4 in | |
| May | 65°F (18°C) | 5.3 in | Wettest |
| June | 74°F (24°C) | 4.1 in | |
| July | 77°F (25°C) | 3.7 in | Warmest |
| August | 75°F (24°C) | 3.2 in | |
| September | 68°F (20°C) | 3.4 in | |
| October | 56°F (13°C) | 2.9 in | |
| November | 44°F (7°C) | 3.6 in | |
| December | 34°F (1°C) | 2.2 in | Driest |
St. Elmo has a seasonal temperature swing of 48°F / from 29°F in January to 77°F in July. Total annual precipitation is 41.2 inches, with May being the wettest month (5.3") and December the driest (2.2").