| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 17°F | 32°F | 24°F | 3.1" |
| February | 18°F | 34°F | 26°F | 3.0" |
| March | 31°F | 49°F | 39°F | 5.2" |
| April | 40°F | 62°F | 50°F | 4.8" |
| May | 51°F | 73°F | 61°F | 5.9" |
| June | 60°F | 82°F | 70°F | 6.7" |
| July | 64°F | 84°F | 73°F | 4.1" |
| August | 62°F | 82°F | 71°F | 7.7" |
| September | 55°F | 76°F | 65°F | 3.2" |
| October | 44°F | 64°F | 53°F | 7.3" |
| November | 33°F | 50°F | 41°F | 3.9" |
| December | 22°F | 36°F | 29°F | 3.7" |
| Index | Plainfield | Illinois | National |
| Air quality index | 60 | 41 | 50 |
| Pollution index | 1,874,490 | 3,347,295 | 5,066,862 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 72 |
| Days with moderate air quality | 281 |
| Days w/ poor A.Q. for sensitive groups | 11 |
| Days with unhealthy air quality | 1 |
| Pollutant | Total |
| Arsenic | 0.002% |
| Benzene | 0.030% |
| Carbon Tetrachloride | 0.010% |
| Lead | 0.010% |
| Mercury | 0.010% |
| City, State | Population | Air Quality Index | National Avg. |
| Big Rock, IL | 1,139 | 1 | 98% |
| Kaneville, IL | 421 | 1 | 98% |
| Plano, IL | 11,929 | 1 | 98% |
| Plattville, IL | 254 | 1 | 98% |
| Lisbon, IL | 397 | 1 | 98% |
| Plainfield, IL | 41,881 | 60 | 20% |
| City, State | Population | Air Quality Index | National Avg. |
| Morgan Hill, CA | 41,839 | 48 | 4% |
| Rohnert Park, CA | 41,928 | 35 | 30% |
| Urbana, IL | 41,941 | 36 | 28% |
| Burleson, TX | 41,962 | 33 | 34% |
| Bozeman, MT | 41,761 | 24 | 52% |
| Plainfield, IL | 41,881 | 60 | 20% |