| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 19°F | 35°F | 27°F | 3.2" |
| February | 20°F | 38°F | 28°F | 2.3" |
| March | 34°F | 53°F | 42°F | 3.3" |
| April | 44°F | 67°F | 54°F | 5.2" |
| May | 54°F | 77°F | 65°F | 5.3" |
| June | 64°F | 85°F | 74°F | 6.5" |
| July | 66°F | 86°F | 76°F | 5.8" |
| August | 65°F | 85°F | 74°F | 9.3" |
| September | 58°F | 80°F | 68°F | 8.3" |
| October | 46°F | 68°F | 56°F | 4.7" |
| November | 35°F | 54°F | 43°F | 4.6" |
| December | 25°F | 40°F | 32°F | 3.9" |
| Index | Bellflower | Illinois | National |
| Air quality index | 42 | 41 | 42 |
| Pollution index | 7,745,200 | 3,148,694 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 281 |
| Days with moderate air quality | 84 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.030% |
| Benzene | 0.070% |
| Carbon Tetrachloride | 0.020% |
| Lead | 0.860% |
| Mercury | 0.210% |
| City | Population | Air Quality Index | National Avg. |
| Gibson City, IL | 3,340 | 42 | 16.0% |
| Mahomet, IL | 8,888 | 42 | 16.0% |
| Farmer City, IL | 2,063 | 42 | 16.0% |
| Fisher, IL | 1,917 | 42 | 16.0% |
| Elliott, IL | 310 | 42 | 16.0% |
| Bellflower, IL | 430 | 42 | 16.0% |
| City | Population | Air Quality Index | National Avg. |
| Chandlerville, IL | 430 | 40 | 20.0% |
| Hope, KS | 430 | 32 | 36.0% |
| Friendsville, MD | 430 | 36 | 28.0% |
| Gunnison, MS | 430 | 43 | 14.0% |
| Momeyer, NC | 430 | 36 | 28.0% |
| Bellflower, IL | 430 | 42 | 16.0% |
Here are the best places to live in Illinois
These are the largest cities in Illinois
Most Dangerous States In The US
Safest States In The US