Quincy, IL
Full City Profile · Illinois · Adams County County
3.9
/5.0
B+
Good
39,188
Population
2,462/sq mi density
$56,372
Median Income
$34,819 per capita
$146,100
Home Value
$182,657 Zillow
$824
Median Rent
26.6% income on rent
54°F
Avg Temperature
B+
Overall
3.9 / 5.0
Good overall score based on economy, affordability, safety and education
B+
Economy
3.6 / 5.0
$56,372 median income, 4.2% unemployment
A+
Affordability
5.0 / 5.0
$146,100 home value, $824/mo rent
B
Education
3.1 / 5.0
26.6% bachelor's degree or higher
Quincy experiences four distinct seasons with an average annual temperature of 54°F (12°C). Winters average 27°F in January while summers reach 77°F in July. Annual precipitation totals 36.5 inches. The area receives 17.0 inches of snow annually. Air quality is rated Good with a median AQI of 42.
Temperature
27°F Jan (-3°C)
77°F Jul (25°C)
| Annual Average | 53.7°F |
| 1% below US avg | |
| January Average | 27°F (-3°C) |
| July Average | 77°F (25°C) |
Geography
| Elevation | 633 ft (193 m) |
| Area | 15.9 sq mi (41.2 km²) |
| Population Density | 2,462/sq mi |
| Coordinates | 39.9337°N, 91.3793°W |
| Timezone | America/Chicago |
| County | Adams County County |
| Nearest Airport | Quincy Regional-Baldwin Field (UIN) 10 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 42.0 |
| Rating | Good |
| Good Days % | 90.1% |
| Unhealthy Days | 0 |
Air Pollutants (EPA 2023)
| Ozone (O₃) | 0.0484 ppm |
Natural Hazard Risk
| Overall Risk | Relatively Low |
| Risk Score | 64.2 / 100 |
| Social Vulnerability | 29.6 / 100 |
| Community Resilience | 92.0 / 100 |
Hazard Breakdown
| Tornado | Relatively Low |
| Hurricane | Very Low |
| Earthquake | Relatively Low |
| Wildfire | Very Low |
| Flood | Relatively Low |
| Hail | Relatively Moderate |
| Strong Wind | Relatively High |
| Heat Wave | Relatively Moderate |
| Winter Weather | Relatively Moderate |
| Lightning | Relatively Moderate |
| Ice Storm | Relatively Low |
| 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 | 27°F (-3°C) | 1.7 in | Coldest, Driest |
| February | 32°F (-0°C) | 1.9 in | |
| March | 42°F (6°C) | 2.5 in | |
| April | 54°F (12°C) | 4.2 in | |
| May | 64°F (18°C) | 4.8 in | Wettest |
| June | 74°F (23°C) | 4.1 in | |
| July | 77°F (25°C) | 3.6 in | Warmest |
| August | 76°F (24°C) | 3.3 in | |
| September | 68°F (20°C) | 3.4 in | |
| October | 56°F (13°C) | 2.7 in | |
| November | 43°F (6°C) | 2.6 in | |
| December | 32°F (0°C) | 1.7 in |
Quincy has a seasonal temperature swing of 50°F / from 27°F in January to 77°F in July. Total annual precipitation is 36.5 inches, with May being the wettest month (4.8") and January the driest (1.7").