| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 14°F | 30°F | 22°F | 3.8" |
| February | 14°F | 32°F | 23°F | 3.4" |
| March | 29°F | 48°F | 37°F | 4.3" |
| April | 39°F | 62°F | 50°F | 4.5" |
| May | 50°F | 74°F | 61°F | 5.4" |
| June | 59°F | 81°F | 70°F | 6.7" |
| July | 61°F | 82°F | 71°F | 6.0" |
| August | 59°F | 81°F | 69°F | 6.4" |
| September | 51°F | 76°F | 63°F | 3.8" |
| October | 41°F | 63°F | 51°F | 7.1" |
| November | 29°F | 48°F | 38°F | 3.9" |
| December | 19°F | 34°F | 26°F | 3.6" |
| Index | Compton | Illinois | National |
| Air quality index | 1 | 41 | 50 |
| Pollution index | 2,097,740 | 3,347,295 | 5,066,862 |
| Measurement | Total |
| Days measured | 351 |
| Days with good air quality | 351 |
| Days with moderate air quality | |
| Days w/ poor A.Q. for sensitive groups | |
| Days with unhealthy air quality |
| Pollutant | Total |
| Arsenic | 0.001% |
| Benzene | 0.060% |
| Carbon Tetrachloride | 0.000% |
| Lead | 0.001% |
| Mercury | 0.300% |
| City, State | Population | Air Quality Index | National Avg. |
| Lee, IL | 358 | 1 | 98% |
| Shabbona, IL | 982 | 1 | 98% |
| Earlville, IL | 1,672 | 1 | 98% |
| Leland, IL | 844 | 1 | 98% |
| Mendota, IL | 7,182 | 1 | 98% |
| Compton, IL | 259 | 1 | 98% |
| City, State | Population | Air Quality Index | National Avg. |
| Somerville, OH | 259 | 6 | 88% |
| Boody, IL | 259 | 39 | 22% |
| Nageezi, NM | 259 | 42 | 16% |
| Emmett, MI | 259 | 52 | 4% |
| Davy, WV | 259 | 295 | 490% |
| Compton, IL | 259 | 1 | 98% |