| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 28°F | 43°F | 34°F | 9.8" |
| February | 26°F | 45°F | 34°F | 4.7" |
| March | 38°F | 60°F | 48°F | 2.9" |
| April | 45°F | 68°F | 56°F | 5.6" |
| May | 56°F | 79°F | 67°F | 3.7" |
| June | 65°F | 88°F | 76°F | 7.6" |
| July | 67°F | 88°F | 77°F | 12.3" |
| August | 70°F | 93°F | 80°F | 7.2" |
| September | 61°F | 85°F | 72°F | 16.1" |
| October | 49°F | 72°F | 59°F | 7.5" |
| November | 38°F | 59°F | 47°F | 11.9" |
| December | 27°F | 42°F | 33°F | 2.9" |
| Index | Hecker | Illinois | National |
| Air quality index | 54 | 41 | 50 |
| Pollution index | 1,232,920 | 3,347,295 | 5,066,862 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 134 |
| Days with moderate air quality | 221 |
| Days w/ poor A.Q. for sensitive groups | 8 |
| Days with unhealthy air quality | 2 |
| Pollutant | Total |
| Arsenic | 0.170% |
| Benzene | 0.030% |
| Carbon Tetrachloride | 0.000% |
| Lead | 0.010% |
| Mercury | 0.290% |
| City, State | Population | Air Quality Index | National Avg. |
| Mascoutah, IL | 7,917 | 54 | 8% |
| Darmstadt, IL | 0 | 54 | 8% |
| St. Libory, IL | 536 | 54 | 8% |
| Baldwin, IL | 328 | 54 | 8% |
| Maeystown, IL | 138 | 54 | 8% |
| Hecker, IL | 519 | 54 | 8% |
| City, State | Population | Air Quality Index | National Avg. |
| Beech Mountain, NC | 519 | 26 | 48% |
| Ellerslie, MD | 519 | 36 | 28% |
| Wattsburg, PA | 519 | 36 | 28% |
| Leeds, ND | 519 | 36 | 28% |
| Hayden, AZ | 519 | 47 | 6% |
| Hecker, IL | 519 | 54 | 8% |
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