| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 24°F | 41°F | 31°F | 5.3" |
| February | 26°F | 43°F | 33°F | 3.7" |
| March | 38°F | 57°F | 46°F | 4.5" |
| April | 47°F | 69°F | 57°F | 8.3" |
| May | 56°F | 77°F | 66°F | 6.2" |
| June | 65°F | 86°F | 75°F | 8.8" |
| July | 67°F | 88°F | 77°F | 7.5" |
| August | 65°F | 87°F | 75°F | 7.1" |
| September | 58°F | 81°F | 68°F | 8.8" |
| October | 47°F | 70°F | 57°F | 6.4" |
| November | 36°F | 57°F | 45°F | 7.2" |
| December | 29°F | 45°F | 36°F | 5.8" |
| Index | Louisville | Illinois | National |
| Air quality index | 40 | 41 | 50 |
| Pollution index | 959,673 | 3,347,295 | 5,066,862 |
| Measurement | Total |
| Days measured | 245 |
| Days with good air quality | 224 |
| Days with moderate air quality | 21 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.001% |
| Benzene | 0.040% |
| Carbon Tetrachloride | 0.000% |
| Lead | 0.000% |
| Mercury | 0.002% |
| City, State | Population | Air Quality Index | National Avg. |
| Clay City, IL | 824 | 40 | 20% |
| Sailor Springs, IL | 99 | 40 | 20% |
| Farina, IL | 647 | 40 | 20% |
| Flora, IL | 4,940 | 40 | 20% |
| Edgewood, IL | 494 | 40 | 20% |
| Louisville, IL | 1,084 | 40 | 20% |
| City, State | Population | Air Quality Index | National Avg. |
| Schaefferstown, PA | 1,084 | 42 | 16% |
| Monongah, WV | 1,084 | 31 | 38% |
| Howland, ME | 1,085 | 31 | 38% |
| Coyne Center, IL | 1,083 | 46 | 8% |
| Molino, FL | 1,083 | 41 | 18% |
| Louisville, IL | 1,084 | 40 | 20% |
Here are the best places to live in Illinois
See the best places to live in & around Louisville
Top 10 best public schools in Louisville
These are the 10 most affordable cities in Illinois