| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 4°F | 21°F | 13°F | 1.0" |
| February | 7°F | 26°F | 16°F | 1.4" |
| March | 21°F | 42°F | 30°F | 1.7" |
| April | 31°F | 57°F | 42°F | 3.3" |
| May | 43°F | 69°F | 56°F | 4.0" |
| June | 53°F | 78°F | 65°F | 3.9" |
| July | 58°F | 83°F | 70°F | 5.3" |
| August | 53°F | 82°F | 67°F | 4.0" |
| September | 47°F | 73°F | 59°F | 3.9" |
| October | 35°F | 58°F | 45°F | 2.6" |
| November | 21°F | 42°F | 30°F | 0.9" |
| December | 7°F | 26°F | 16°F | 1.8" |
| Index | Overly | North Dakota | National |
| Air quality index | 36 | 35 | 42 |
| Pollution index | 408,578 | 1,038,665 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 320 |
| Days with moderate air quality | 45 |
| 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 | 0.001% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| East Dunseith, ND | 435 | 36 | 28.0% |
| Shell Valley, ND | 1,541 | 36 | 28.0% |
| Willow City, ND | 150 | 36 | 28.0% |
| Bottineau, ND | 2,017 | 36 | 28.0% |
| Barton, ND | 0 | 36 | 28.0% |
| Overly, ND | 15 | 36 | 28.0% |
| City | Population | Air Quality Index | National Avg. |
| Nikolski, AK | 15 | 31 | 38.0% |
| Scott, AR | 15 | 45 | 10.0% |
| Eagleville, CA | 15 | 29 | 42.0% |
| Frederick, KS | 15 | 40 | 20.0% |
| Concord, KY | 15 | 14 | 72.0% |
| Overly, ND | 15 | 36 | 28.0% |
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