All Countries
Thayer, IL
Full City Profile · Illinois · Sangamon County County
3.0
/5.0
B
Good
638
Population
1,046/sq mi density
$63,125
Median Income
$36,853 per capita
$87,300
Home Value
$119,208 Zillow
$919
Median Rent
30.8% income on rent
55°F
Avg Temperature
302 sunny days/yr
152
Violent Crime/100K
304 property/100K
B
Overall
3.0 / 5.0
Good overall score based on economy, affordability, safety and education
A
Economy
4.0 / 5.0
$63,125 median income, 3.3% unemployment
A+
Affordability
5.0 / 5.0
$87,300 home value, $919/mo rent
F
Safety
1.0 / 5.0
152 violent crimes/100K
D
Education
1.9 / 5.0
11.2% bachelor's degree or higher
Thayer 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. The area gets 302 sunny days per year. 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 43.
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) |
| Sunny Days | 302 days/yr |
Geography
| Elevation | 639 ft (195 m) |
| Area | 0.2 sq mi (0.6 km²) |
| Population Density | 1,046/sq mi |
| Coordinates | 39.5404°N, 89.7580°W |
| Timezone | America/Chicago |
| County | Sangamon County County |
| Nearest Airport | St Louis Regional (ALN) 48 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 | 29°F (-2°C) | 1.7 in | Coldest, Driest |
| February | 31°F (-1°C) | 1.9 in | |
| March | 42°F (6°C) | 3.3 in | |
| April | 53°F (12°C) | 3.7 in | |
| May | 64°F (18°C) | 4.3 in | Wettest |
| June | 72°F (22°C) | 3.9 in | |
| July | 77°F (25°C) | 3.7 in | Warmest |
| August | 74°F (23°C) | 3.4 in | |
| September | 67°F (20°C) | 3.3 in | |
| October | 56°F (13°C) | 2.6 in | |
| November | 43°F (6°C) | 3.0 in | |
| December | 31°F (-1°C) | 2.7 in |
Thayer has a seasonal temperature swing of 49°F / from 29°F in January to 77°F in July. Total annual precipitation is 37.5 inches, with May being the wettest month (4.3") and January the driest (1.7").