| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 15°F | 33°F | 24°F | 0.7" |
| February | 17°F | 36°F | 26°F | 1.1" |
| March | 31°F | 52°F | 40°F | 2.3" |
| April | 41°F | 65°F | 52°F | 4.7" |
| May | 51°F | 74°F | 62°F | 5.0" |
| June | 62°F | 83°F | 72°F | 6.5" |
| July | 65°F | 86°F | 75°F | 4.5" |
| August | 63°F | 84°F | 73°F | 5.2" |
| September | 54°F | 78°F | 65°F | 3.7" |
| October | 43°F | 65°F | 53°F | 3.0" |
| November | 32°F | 52°F | 41°F | 2.0" |
| December | 20°F | 36°F | 28°F | 1.9" |
| Index | Ottumwa | Iowa | National |
| Air quality index | 29 | 39 | 42 |
| Pollution index | 464,333 | 1,154,535 | 2,726,193 |
| Measurement | Total |
| Days measured | 120 |
| Days with good air quality | 101 |
| Days with moderate air quality | 19 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.000% |
| Benzene | 0.010% |
| Carbon Tetrachloride | 0.001% |
| Lead | 0.320% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Agency, IA | 625 | 29 | 42.0% |
| Batavia, IA | 557 | 29 | 42.0% |
| Floris, IA | 133 | 29 | 42.0% |
| Eldon, IA | 921 | 29 | 42.0% |
| Chillicothe, IA | 99 | 35 | 30.0% |
| Ottumwa, IA | 24,505 | 29 | 42.0% |
| City | Population | Air Quality Index | National Avg. |
| Key West, FL | 24,495 | 34 | 32.0% |
| Collinsville, IL | 24,489 | 54 | 8.0% |
| Homer Glen, IL | 24,521 | 55 | 10.0% |
| Watauga, TX | 24,487 | 51 | 2.0% |
| Coronado, CA | 24,526 | 64 | 28.0% |
| Ottumwa, IA | 24,505 | 29 | 42.0% |
Here are the best places to live in Iowa
These are the 10 cheapest cities in Iowa
These are the largest cities in Iowa
Safest Cities In The US