Gridley, IL
Full City Profile · Illinois · McLean County County
4.2
/5.0
A
Great
1,339
Population
1,089/sq mi density
$69,688
Median Income
$35,440 per capita
$134,600
Home Value
$218,085 Zillow
$763
Median Rent
21.5% income on rent
51°F
Avg Temperature
A
Overall
4.2 / 5.0
Strong
A
Economy
4.3 / 5.0
$69,688 median income, 2.9% unemployment
A+
Affordability
5.0 / 5.0
$134,600 home value, $763/mo rent
B
Education
3.4 / 5.0
30.3% bachelor's degree or higher
Gridley experiences four distinct seasons with an average annual temperature of 51°F (11°C). Winters average 23°F in January while summers reach 73°F in July. Annual precipitation totals 36.3 inches. The area receives 19.9 inches of snow annually. Air quality is rated Good with a median AQI of 44.
Temperature
23°F Jan (-5°C)
73°F Jul (23°C)
| Annual Average | 50.5°F |
| 6% below US avg | |
| January Average | 23°F (-5°C) |
| July Average | 73°F (23°C) |
Geography
| Elevation | 756 ft (230 m) |
| Area | 0.5 sq mi (1.2 km²) |
| Population Density | 1,089/sq mi |
| Coordinates | 40.7437°N, 88.8809°W |
| Timezone | America/Chicago |
| County | McLean County County |
| Nearest Airport | Central Il Regional/Bloomington-Normal (BMI) 19 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 44.0 |
| Rating | Good |
| Good Days % | 69.4% |
| Unhealthy Days | 1 |
Air Pollutants (EPA 2023)
| Ozone (O₃) | 0.0482 ppm |
| PM2.5 (Fine Particles) | 8.8 μg/m³ |
Natural Hazard Risk
| Overall Risk | Relatively Moderate |
| Risk Score | 86.9 / 100 |
| Social Vulnerability | 15.1 / 100 |
| Community Resilience | 95.5 / 100 |
Hazard Breakdown
| Tornado | Relatively Moderate |
| Hurricane | Very Low |
| Earthquake | Relatively Low |
| Wildfire | Very Low |
| Flood | Relatively Moderate |
| Hail | Relatively Moderate |
| Strong Wind | Relatively Moderate |
| Heat Wave | Relatively Moderate |
| Winter Weather | Relatively High |
| Lightning | Relatively Moderate |
| Ice Storm | Relatively Moderate |
| Drought | Relatively High |
| Cold Wave | Relatively High |
| Landslide | Very Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 23°F (-5°C) | 2.2 in | Coldest |
| February | 28°F (-2°C) | 1.6 in | Driest |
| March | 39°F (4°C) | 2.7 in | |
| April | 51°F (10°C) | 3.6 in | |
| May | 62°F (17°C) | 4.5 in | Wettest |
| June | 71°F (22°C) | 3.8 in | |
| July | 73°F (23°C) | 3.7 in | Warmest |
| August | 72°F (22°C) | 3.2 in | |
| September | 65°F (18°C) | 3.1 in | |
| October | 53°F (12°C) | 3.2 in | |
| November | 40°F (4°C) | 2.6 in | |
| December | 29°F (-2°C) | 2.0 in |
Gridley has a seasonal temperature swing of 50°F / from 23°F in January to 73°F in July. Total annual precipitation is 36.3 inches, with May being the wettest month (4.5") and February the driest (1.6").