Nilwood, IL
Full City Profile · Illinois · Macoupin County County
3.3
/5.0
B
Good
140
Population
298/sq mi density
$46,563
Median Income
$23,041 per capita
$44,400
Home Value
$152,828 Zillow
55°F
Avg Temperature
B
Overall
3.3 / 5.0
Good overall score based on economy, affordability, safety and education
B
Economy
3.0 / 5.0
$46,563 median income, 5.8% unemployment
A+
Affordability
5.0 / 5.0
$44,400 home value, /mo rent
D
Education
1.8 / 5.0
9.5% bachelor's degree or higher
Nilwood 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 38.4 inches. The area receives 16.1 inches of snow annually. Air quality is rated Good with a median AQI of 35.
Temperature
29°F Jan (-2°C)
77°F Jul (25°C)
| Annual Average | 54.8°F |
| 1% above US avg | |
| January Average | 29°F (-2°C) |
| July Average | 77°F (25°C) |
Geography
| Elevation | 670 ft (204 m) |
| Area | 0.2 sq mi (0.5 km²) |
| Population Density | 298/sq mi |
| Coordinates | 39.3995°N, 89.8077°W |
| Timezone | America/Chicago |
| County | Macoupin County County |
| Nearest Airport | St Louis Regional (ALN) 37 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 35.0 |
| Rating | Good |
| Good Days % | 93.4% |
| Unhealthy Days | 1 |
Air Pollutants (EPA 2023)
| Ozone (O₃) | 0.0477 ppm |
| NO₂ (Nitrogen Dioxide) | 3.9 ppb |
| SO₂ (Sulfur Dioxide) | 0.61 ppb |
Natural Hazard Risk
| Overall Risk | Relatively Low |
| Risk Score | 79.9 / 100 |
| Social Vulnerability | 50.7 / 100 |
| Community Resilience | 72.7 / 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 Moderate |
| Lightning | Relatively High |
| 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 | 29°F (-2°C) | 2.0 in | Coldest, Driest |
| February | 33°F (1°C) | 2.3 in | |
| March | 44°F (7°C) | 2.5 in | |
| April | 56°F (13°C) | 4.2 in | |
| May | 65°F (19°C) | 4.2 in | |
| June | 74°F (23°C) | 4.3 in | Wettest |
| July | 77°F (25°C) | 3.5 in | Warmest |
| August | 76°F (24°C) | 3.1 in | |
| September | 69°F (21°C) | 3.4 in | |
| October | 57°F (14°C) | 3.4 in | |
| November | 44°F (7°C) | 3.1 in | |
| December | 34°F (1°C) | 2.4 in |
Nilwood has a seasonal temperature swing of 49°F / from 29°F in January to 77°F in July. Total annual precipitation is 38.4 inches, with June being the wettest month (4.3") and January the driest (2.0").