| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 12°F | 30°F | 21°F | 0.7" |
| February | 14°F | 33°F | 23°F | 0.7" |
| March | 29°F | 49°F | 38°F | 2.1" |
| April | 39°F | 63°F | 50°F | 5.0" |
| May | 50°F | 74°F | 61°F | 5.9" |
| June | 60°F | 83°F | 71°F | 6.0" |
| July | 63°F | 85°F | 74°F | 5.1" |
| August | 61°F | 83°F | 71°F | 6.0" |
| September | 52°F | 77°F | 64°F | 4.5" |
| October | 41°F | 64°F | 52°F | 3.4" |
| November | 29°F | 50°F | 38°F | 1.8" |
| December | 17°F | 34°F | 25°F | 1.5" |
| Index | Alleman | Iowa | National |
| Air quality index | 37 | 39 | 42 |
| Pollution index | 9,310,160 | 1,154,535 | 2,726,193 |
| Measurement | Total |
| Days measured | 214 |
| Days with good air quality | 210 |
| Days with moderate air quality | 4 |
| Days w/ poor A.Q. for sensitive groups | |
| Days with unhealthy air quality |
| Pollutant | Total |
| Arsenic | 0.010% |
| Benzene | 0.110% |
| Carbon Tetrachloride | 0.080% |
| Lead | 0.030% |
| Mercury | 0.010% |
| City | Population | Air Quality Index | National Avg. |
| Ames, IA | 68,047 | 37 | 26.0% |
| Nevada, IA | 6,959 | 37 | 26.0% |
| Cambridge, IA | 978 | 37 | 26.0% |
| Huxley, IA | 4,000 | 37 | 26.0% |
| Sheldahl, IA | 346 | 37 | 26.0% |
| Alleman, IA | 447 | 37 | 26.0% |
| City | Population | Air Quality Index | National Avg. |
| Moreland, GA | 447 | 52 | 4.0% |
| Spring Grove, IN | 447 | 6 | 88.0% |
| Friendsville, MD | 447 | 36 | 28.0% |
| Fortine, MT | 447 | 37 | 26.0% |
| Phillipsburg, OH | 447 | 47 | 6.0% |
| Alleman, IA | 447 | 37 | 26.0% |