| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 17°F | 34°F | 24°F | 3.4" |
| February | 18°F | 36°F | 26°F | 3.6" |
| March | 32°F | 52°F | 41°F | 3.5" |
| April | 41°F | 65°F | 52°F | 6.9" |
| May | 52°F | 74°F | 63°F | 7.1" |
| June | 62°F | 83°F | 72°F | 7.9" |
| July | 65°F | 86°F | 75°F | 8.4" |
| August | 63°F | 84°F | 73°F | 7.4" |
| September | 54°F | 78°F | 65°F | 8.9" |
| October | 44°F | 66°F | 54°F | 5.8" |
| November | 32°F | 52°F | 41°F | 4.0" |
| December | 22°F | 37°F | 29°F | 4.5" |
| Index | Maquon | Illinois | National |
| Air quality index | 48 | 41 | 50 |
| Pollution index | 1,709,230 | 3,347,295 | 5,066,862 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 207 |
| Days with moderate air quality | 132 |
| Days w/ poor A.Q. for sensitive groups | 21 |
| Days with unhealthy air quality | 5 |
| Pollutant | Total |
| Arsenic | 0.001% |
| Benzene | 0.050% |
| Carbon Tetrachloride | 0.040% |
| Lead | 0.001% |
| Mercury | 0.001% |
| City, State | Population | Air Quality Index | National Avg. |
| Avon, IL | 803 | 48 | 4% |
| Elmwood, IL | 2,262 | 48 | 4% |
| Gilson, IL | 160 | 48 | 4% |
| Oak Run, IL | 528 | 48 | 4% |
| Brimfield, IL | 998 | 48 | 4% |
| Maquon, IL | 334 | 48 | 4% |
| City, State | Population | Air Quality Index | National Avg. |
| Weissport, PA | 334 | 47 | 6% |
| Post Lake, WI | 334 | 36 | 28% |
| Zihlman, MD | 334 | 32 | 36% |
| Butlertown, MD | 334 | 46 | 8% |
| Jeff, KY | 334 | 36 | 28% |
| Maquon, IL | 334 | 48 | 4% |