| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 9°F | 25°F | 17°F | 0.7" |
| February | 11°F | 29°F | 20°F | 1.1" |
| March | 25°F | 44°F | 34°F | 2.2" |
| April | 36°F | 60°F | 47°F | 5.1" |
| May | 48°F | 71°F | 59°F | 5.0" |
| June | 58°F | 81°F | 69°F | 5.4" |
| July | 61°F | 84°F | 72°F | 4.2" |
| August | 59°F | 82°F | 70°F | 4.0" |
| September | 51°F | 76°F | 62°F | 4.3" |
| October | 38°F | 62°F | 49°F | 2.7" |
| November | 26°F | 47°F | 36°F | 1.5" |
| December | 13°F | 29°F | 21°F | 1.4" |
| Index | Manly | Iowa | National |
| Air quality index | 15 | 39 | 42 |
| Pollution index | 1,444,380 | 1,154,535 | 2,726,193 |
| Measurement | Total |
| Days measured | 118 |
| Days with good air quality | 118 |
| Days with moderate air quality | 0 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.001% |
| Benzene | 0.040% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.010% |
| Mercury | 0.001% |
| City | Population | Air Quality Index | National Avg. |
| Fertile, IA | 295 | 15 | 70.0% |
| Bolan, IA | 10 | 15 | 70.0% |
| Mona, IA | 39 | 15 | 70.0% |
| Rock Falls, IA | 161 | 15 | 70.0% |
| Portland, IA | 27 | 15 | 70.0% |
| Manly, IA | 1,480 | 15 | 70.0% |
| City | Population | Air Quality Index | National Avg. |
| Island Heights, NJ | 1,480 | 41 | 18.0% |
| St. David, AZ | 1,481 | 45 | 10.0% |
| Lewiston, CA | 1,481 | 42 | 16.0% |
| Greenfield, IL | 1,481 | 40 | 20.0% |
| Markle, IN | 1,481 | 31 | 38.0% |
| Manly, IA | 1,480 | 15 | 70.0% |
Here are the best places to live in Iowa
Most Dangerous States In The US
Check out the 10 safest cities in Iowa
See the best places to live in Manly