| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 13°F | 30°F | 20°F | 0.7" |
| February | 16°F | 36°F | 24°F | 2.3" |
| March | 30°F | 53°F | 39°F | 6.6" |
| April | 39°F | 62°F | 49°F | 7.4" |
| May | 52°F | 75°F | 62°F | 7.0" |
| June | 63°F | 84°F | 72°F | 22.2" |
| July | 67°F | 88°F | 77°F | 6.3" |
| August | 64°F | 86°F | 73°F | 3.9" |
| September | 56°F | 82°F | 67°F | 4.2" |
| October | 44°F | 67°F | 53°F | 7.3" |
| November | 29°F | 52°F | 38°F | 2.0" |
| December | 14°F | 31°F | 21°F | 2.9" |
| Index | Viborg | South Dakota | National |
| Air quality index | 36 | 36 | 42 |
| Pollution index | 482,612 | 345,623 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 321 |
| Days with moderate air quality | 43 |
| Days w/ poor A.Q. for sensitive groups | 1 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.000% |
| Benzene | 0.010% |
| Carbon Tetrachloride | 0.001% |
| Lead | 0.004% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Centerville, SD | 989 | 36 | 28.0% |
| Hurley, SD | 424 | 36 | 28.0% |
| Chancellor, SD | 303 | 36 | 28.0% |
| Irene, SD | 570 | 36 | 28.0% |
| Davis, SD | 97 | 36 | 28.0% |
| Viborg, SD | 823 | 36 | 28.0% |
| City | Population | Air Quality Index | National Avg. |
| Hopedale, IL | 823 | 44 | 12.0% |
| Pentwater, MI | 823 | 38 | 24.0% |
| New Florence, MO | 823 | 39 | 22.0% |
| Efland, NC | 823 | 44 | 12.0% |
| Moncure, NC | 823 | 29 | 42.0% |
| Viborg, SD | 823 | 36 | 28.0% |