| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 25°F | 39°F | 31°F | 6.1" |
| February | 23°F | 37°F | 29°F | 2.4" |
| March | 37°F | 55°F | 45°F | 4.1" |
| April | 44°F | 65°F | 53°F | 3.9" |
| May | 55°F | 77°F | 65°F | 2.6" |
| June | 64°F | 85°F | 75°F | 4.7" |
| July | 65°F | 86°F | 75°F | 8.2" |
| August | 68°F | 88°F | 77°F | 7.2" |
| September | 59°F | 83°F | 71°F | 8.1" |
| October | 49°F | 69°F | 58°F | 8.2" |
| November | 36°F | 54°F | 44°F | 3.6" |
| December | 25°F | 38°F | 31°F | 2.6" |
| Index | Windsor | Illinois | National |
| Air quality index | 40 | 41 | 42 |
| Pollution index | 2,357,280 | 3,148,694 | 2,726,193 |
| 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 | 0.002% |
| Benzene | 0.030% |
| Carbon Tetrachloride | 0.004% |
| Lead | 0.010% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Cowden, IL | 538 | 40 | 20.0% |
| Neoga, IL | 1,579 | 40 | 20.0% |
| Sigel, IL | 419 | 40 | 20.0% |
| Stewardson, IL | 710 | 40 | 20.0% |
| Strasburg, IL | 528 | 40 | 20.0% |
| Windsor, IL | 1,150 | 40 | 20.0% |
| City | Population | Air Quality Index | National Avg. |
| Dunnavant, AL | 1,150 | 53 | 6.0% |
| Bethany Beach, DE | 1,150 | 36 | 28.0% |
| Cottage City, MD | 1,150 | 47 | 6.0% |
| Mound City, MO | 1,150 | 43 | 14.0% |
| Ninnekah, OK | 1,150 | 43 | 14.0% |
| Windsor, IL | 1,150 | 40 | 20.0% |
Here are the best places to live in Illinois
See the best places to live in Windsor
Check out the 10 safest cities in Illinois
Most Dangerous Cities In The US