| 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 | 50 |
| Pollution index | 2,357,280 | 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 | 0.002% |
| Benzene | 0.030% |
| Carbon Tetrachloride | 0.004% |
| Lead | 0.010% |
| Mercury | 0.000% |
| City, State | Population | Air Quality Index | National Avg. |
| Cowden, IL | 534 | 40 | 20% |
| Neoga, IL | 1,770 | 40 | 20% |
| Sigel, IL | 349 | 40 | 20% |
| Stewardson, IL | 719 | 40 | 20% |
| Strasburg, IL | 501 | 40 | 20% |
| Windsor, IL | 1,460 | 40 | 20% |
| City, State | Population | Air Quality Index | National Avg. |
| Hazen, AR | 1,460 | 45 | 10% |
| Sunrise Lake, PA | 1,460 | 34 | 32% |
| Pheasant Run, OH | 1,459 | 50 | = 100 |
| Poultney, VT | 1,459 | 36 | 28% |
| Granger, IA | 1,461 | 39 | 22% |
| Windsor, IL | 1,460 | 40 | 20% |
Here are the best places to live in Illinois
See the best places to live in & around Windsor
Top 10 cities in Illinois with the best education system
These are the 10 most affordable cities in Illinois