| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 9°F | 24°F | 16°F | 0.3" |
| February | 11°F | 27°F | 18°F | 0.3" |
| March | 26°F | 42°F | 33°F | 1.2" |
| April | 38°F | 58°F | 46°F | 2.8" |
| May | 49°F | 70°F | 59°F | 2.7" |
| June | 59°F | 79°F | 68°F | 5.8" |
| July | 63°F | 83°F | 72°F | 4.9" |
| August | 60°F | 80°F | 69°F | 3.2" |
| September | 52°F | 74°F | 62°F | 3.4" |
| October | 41°F | 59°F | 49°F | 2.0" |
| November | 28°F | 45°F | 36°F | 0.6" |
| December | 15°F | 28°F | 21°F | 0.6" |
| Index | Otranto | Iowa | National |
| Air quality index | 15 | 39 | 42 |
| Pollution index | 1,320,050 | 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 | 0.010% |
| Benzene | 0.040% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.010% |
| Mercury | 0.010% |
| City | Population | Air Quality Index | National Avg. |
| Kensett, IA | 285 | 15 | 70.0% |
| Mitchell, IA | 142 | 15 | 70.0% |
| Plymouth, IA | 466 | 15 | 70.0% |
| Glenville, MN | 631 | 15 | 70.0% |
| Bolan, IA | 10 | 15 | 70.0% |
| Otranto, IA | 0 | 15 | 70.0% |
| City | Population | Air Quality Index | National Avg. |
| Chase, AK | 0 | 31 | 38.0% |
| Chiniak, AK | 0 | 31 | 38.0% |
| Chisana, AK | 0 | 31 | 38.0% |
| Dot Lake, AK | 0 | 38 | 24.0% |
| Eureka Roadhouse, AK | 0 | 31 | 38.0% |
| Otranto, IA | 0 | 15 | 70.0% |
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