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Chatham, IL
Full City Profile · Illinois · Sangamon County County
4.0
/5.0
A
Great
14,740
Population
1,989/sq mi density
$106,030
Median Income
$46,957 per capita
$231,900
Home Value
$296,201 Zillow
$1,157
Median Rent
25.9% income on rent
53°F
Avg Temperature
293 sunny days/yr
47
Violent Crime/100K
703 property/100K
A
Overall
4.0 / 5.0
Strong
A+
Economy
4.9 / 5.0
$106,030 median income, 2.5% unemployment
A+
Affordability
5.0 / 5.0
$231,900 home value, $1,157/mo rent
F
Safety
1.0 / 5.0
47 violent crimes/100K
A+
Education
5.0 / 5.0
49.4% bachelor's degree or higher
Chatham experiences four distinct seasons with an average annual temperature of 53°F (12°C). Winters average 27°F in January while summers reach 76°F in July. The area gets 293 sunny days per year. Annual precipitation totals 40.5 inches. Air quality is rated Good with a median AQI of 43.
Temperature
27°F Jan (-3°C)
76°F Jul (24°C)
| Annual Average | 52.9°F |
| 2% below US avg | |
| January Average | 27°F (-3°C) |
| July Average | 76°F (24°C) |
| Sunny Days | 293 days/yr |
Geography
| Elevation | 598 ft (182 m) |
| Area | 2.7 sq mi (7.0 km²) |
| Population Density | 1,989/sq mi |
| Coordinates | 39.6745°N, 89.6933°W |
| Timezone | America/Chicago |
| County | Sangamon County County |
| Nearest Airport | St Louis Regional (ALN) 57 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 43.0 |
| Rating | Good |
Air Pollutants (EPA 2023)
| Ozone (O₃) | 0.0483 ppm |
| PM2.5 (Fine Particles) | 8.9 μg/m³ |
Natural Hazard Risk
| Overall Risk | Relatively Moderate |
| Risk Score | 91.7 / 100 |
| Social Vulnerability | 32.0 / 100 |
| Community Resilience | 92.2 / 100 |
Hazard Breakdown
| Tornado | Relatively High |
| Hurricane | Very Low |
| Earthquake | Relatively Moderate |
| Wildfire | Very Low |
| Flood | Relatively Moderate |
| Hail | Relatively High |
| Strong Wind | Relatively High |
| Heat Wave | Relatively Moderate |
| Winter Weather | Relatively High |
| Lightning | Relatively High |
| Ice Storm | Relatively Moderate |
| Drought | Relatively High |
| Cold Wave | Relatively High |
| Landslide | Relatively Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 27°F (-3°C) | 1.7 in | Coldest, Driest |
| February | 30°F (-1°C) | 1.8 in | |
| March | 42°F (5°C) | 3.2 in | |
| April | 53°F (12°C) | 3.6 in | |
| May | 64°F (18°C) | 4.2 in | Wettest |
| June | 73°F (23°C) | 3.9 in | |
| July | 76°F (24°C) | 3.6 in | Warmest |
| August | 74°F (23°C) | 3.4 in | |
| September | 67°F (20°C) | 3.2 in | |
| October | 55°F (13°C) | 2.6 in | |
| November | 42°F (6°C) | 2.9 in | |
| December | 31°F (-1°C) | 2.6 in |
Chatham has a seasonal temperature swing of 49°F / from 27°F in January to 76°F in July. Total annual precipitation is 36.8 inches, with May being the wettest month (4.2") and January the driest (1.7").