| 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 | Johnsonville | Illinois | National |
| Air quality index | 43 | 41 | 42 |
| Pollution index | 500,004 | 3,148,694 | 2,726,193 |
| Measurement | Total |
| Days measured | 344 |
| Days with good air quality | 269 |
| Days with moderate air quality | 74 |
| Days w/ poor A.Q. for sensitive groups | 1 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.001% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.000% |
| Lead | 0.000% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Flora, IL | 4,686 | 40 | 20.0% |
| Clay City, IL | 896 | 40 | 20.0% |
| Keenes, IL | 53 | 43 | 14.0% |
| Cisne, IL | 505 | 43 | 14.0% |
| Sims, IL | 167 | 43 | 14.0% |
| Johnsonville, IL | 50 | 43 | 14.0% |
| City | Population | Air Quality Index | National Avg. |
| Tonopah, AZ | 50 | 74 | 48.0% |
| Fish Camp, CA | 50 | 50 | = 100 |
| Lookout, CA | 50 | 29 | 42.0% |
| Idalia, CO | 50 | 58 | 16.0% |
| Pine Island, FL | 50 | 30 | 40.0% |
| Johnsonville, IL | 50 | 43 | 14.0% |
Here are the best places to live in Illinois
Check out the 10 safest cities in Illinois
Most Dangerous States In The US
See the best places to live in Johnsonville