| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 19°F | 35°F | 27°F | 2.3" |
| February | 20°F | 37°F | 28°F | 2.0" |
| March | 30°F | 50°F | 39°F | 2.5" |
| April | 40°F | 64°F | 51°F | 3.7" |
| May | 51°F | 74°F | 62°F | 3.7" |
| June | 61°F | 83°F | 71°F | 4.6" |
| July | 63°F | 85°F | 74°F | 4.0" |
| August | 61°F | 84°F | 72°F | 3.5" |
| September | 55°F | 78°F | 66°F | 2.9" |
| October | 44°F | 66°F | 54°F | 2.6" |
| November | 33°F | 53°F | 43°F | 2.5" |
| December | 25°F | 40°F | 32°F | 2.7" |
| Index | Ottawa | Ohio | National |
| Air quality index | 39 | 40 | 42 |
| Pollution index | 2,673,850 | 4,472,386 | 2,726,193 |
| Measurement | Total |
| Days measured | 364 |
| Days with good air quality | 303 |
| Days with moderate air quality | 61 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.002% |
| Benzene | 0.030% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.010% |
| Mercury | 0.010% |
| City | Population | Air Quality Index | National Avg. |
| Bluffton, OH | 4,024 | 39 | 22.0% |
| Pandora, OH | 1,250 | 39 | 22.0% |
| Kalida, OH | 1,679 | 39 | 22.0% |
| Belmore, OH | 63 | 39 | 22.0% |
| Miller City, OH | 142 | 39 | 22.0% |
| Ottawa, OH | 4,349 | 39 | 22.0% |
| City | Population | Air Quality Index | National Avg. |
| El Jebel, CO | 4,349 | 44 | 12.0% |
| Euharlee, GA | 4,348 | 44 | 12.0% |
| Lake of the Pines, CA | 4,350 | 44 | 12.0% |
| Beach Haven West, NJ | 4,350 | 37 | 26.0% |
| Nanaimo H, BC | 4,347 | n/a | |
| Ottawa, OH | 4,349 | 39 | 22.0% |
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