| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 16°F | 36°F | 24°F | 0.9" |
| February | 17°F | 38°F | 26°F | 1.0" |
| March | 28°F | 52°F | 38°F | 2.4" |
| April | 38°F | 62°F | 48°F | 5.9" |
| May | 48°F | 72°F | 59°F | 5.6" |
| June | 59°F | 82°F | 70°F | 6.4" |
| July | 64°F | 88°F | 75°F | 5.6" |
| August | 61°F | 84°F | 72°F | 6.9" |
| September | 52°F | 78°F | 63°F | 6.3" |
| October | 40°F | 64°F | 50°F | 5.7" |
| November | 27°F | 51°F | 38°F | 2.0" |
| December | 16°F | 35°F | 25°F | 1.2" |
| Index | Fairfax | South Dakota | National |
| Air quality index | 36 | 36 | 42 |
| Pollution index | 179,967 | 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 | 0.002% |
| Carbon Tetrachloride | 0.000% |
| Lead | 0.000% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Anoka, NE | 35 | 36 | 28.0% |
| Bonesteel, SD | 386 | 36 | 28.0% |
| Butte, NE | 348 | 36 | 28.0% |
| St. Charles, SD | 8 | 36 | 28.0% |
| Naper, NE | 83 | 36 | 28.0% |
| Fairfax, SD | 138 | 36 | 28.0% |
| City | Population | Air Quality Index | National Avg. |
| Reader, AR | 138 | 32 | 36.0% |
| Winchester, AR | 138 | 43 | 14.0% |
| Jackson Lake, CO | 138 | 45 | 10.0% |
| Trail Side, CO | 138 | 45 | 10.0% |
| Jersey, GA | 138 | 44 | 12.0% |
| Fairfax, SD | 138 | 36 | 28.0% |
Here are the best places to live in South Dakota
Check out the 10 most dangerous cities in South Dakota
Safest States In The US
Most Dangerous Cities In The US