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Marietta, IL
Full City Profile · Illinois · Fulton County County
3.1
/5.0
B
Good
110
Population
407/sq mi density
$57,188
Median Income
$27,635 per capita
$81,700
Home Value
$68,013 Zillow
53°F
Avg Temperature
275 sunny days/yr
280
Violent Crime/100K
1,557 property/100K
B
Overall
3.1 / 5.0
Good overall score based on economy, affordability, safety and education
B+
Economy
3.9 / 5.0
$57,188 median income, 3.6% unemployment
A+
Affordability
5.0 / 5.0
$81,700 home value, /mo rent
F
Safety
1.0 / 5.0
280 violent crimes/100K
C+
Education
2.6 / 5.0
20.3% bachelor's degree or higher
Marietta experiences four distinct seasons with an average annual temperature of 53°F (12°C). Winters average 25°F in January while summers reach 77°F in July. The area gets 275 sunny days per year. Annual precipitation totals 41.0 inches. The area receives 27.9 inches of snow annually. Air quality is rated Good with a median AQI of 43.
Temperature
25°F Jan (-4°C)
77°F Jul (25°C)
| Annual Average | 52.5°F |
| 3% below US avg | |
| January Average | 25°F (-4°C) |
| July Average | 77°F (25°C) |
| Sunny Days | 275 days/yr |
Geography
| Elevation | 640 ft (195 m) |
| Area | 0.1 sq mi (0.3 km²) |
| Population Density | 407/sq mi |
| Coordinates | 40.4995°N, 90.3930°W |
| Timezone | America/Chicago |
| County | Fulton County County |
| Nearest Airport | General Downing - Peoria International (PIA) 38 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 43.0 |
| Rating | Good |
Natural Hazard Risk
| Overall Risk | Relatively Low |
| Risk Score | 59.0 / 100 |
| Social Vulnerability | 35.9 / 100 |
| Community Resilience | 77.6 / 100 |
Hazard Breakdown
| Tornado | Relatively Moderate |
| Hurricane | Very Low |
| Earthquake | Relatively Low |
| Wildfire | Very Low |
| Flood | Relatively Low |
| Hail | Relatively Moderate |
| Strong Wind | Relatively Moderate |
| Heat Wave | Relatively Low |
| Winter Weather | Relatively Low |
| Lightning | Relatively Low |
| Ice Storm | Relatively Moderate |
| Drought | Relatively Moderate |
| Cold Wave | Relatively Moderate |
| Landslide | Relatively Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 25°F (-4°C) | 1.5 in | Coldest |
| February | 29°F (-2°C) | 1.4 in | Driest |
| March | 40°F (5°C) | 3.0 in | |
| April | 52°F (11°C) | 3.7 in | |
| May | 63°F (17°C) | 4.0 in | |
| June | 72°F (22°C) | 3.9 in | |
| July | 77°F (25°C) | 4.1 in | Warmest, Wettest |
| August | 73°F (23°C) | 3.5 in | |
| September | 66°F (19°C) | 3.9 in | |
| October | 54°F (12°C) | 3.0 in | |
| November | 41°F (5°C) | 2.8 in | |
| December | 29°F (-2°C) | 2.3 in |
Marietta has a seasonal temperature swing of 52°F / from 25°F in January to 77°F in July. Total annual precipitation is 37.1 inches, with July being the wettest month (4.1") and February the driest (1.4").