| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 17°F | 39°F | 27°F | 0.6" |
| February | 20°F | 43°F | 30°F | 0.9" |
| March | 33°F | 58°F | 44°F | 2.0" |
| April | 43°F | 68°F | 54°F | 4.3" |
| May | 53°F | 77°F | 64°F | 4.6" |
| June | 64°F | 86°F | 75°F | 6.0" |
| July | 67°F | 89°F | 78°F | 4.0" |
| August | 64°F | 87°F | 75°F | 4.7" |
| September | 56°F | 81°F | 67°F | 3.5" |
| October | 44°F | 69°F | 55°F | 3.1" |
| November | 32°F | 56°F | 43°F | 1.5" |
| December | 21°F | 40°F | 30°F | 1.9" |
| Index | Fairfax | Missouri | National |
| Air quality index | 43 | 97 | 42 |
| Pollution index | 480,193 | 1,630,255 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 283 |
| Days with moderate air quality | 82 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.001% |
| Benzene | 0.010% |
| Carbon Tetrachloride | 0.000% |
| Lead | 0.001% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Brownville, NE | 125 | 31 | 38.0% |
| Watson, MO | 38 | 40 | 20.0% |
| Craig, MO | 137 | 43 | 14.0% |
| Corning, MO | 5 | 43 | 14.0% |
| Mound City, MO | 1,150 | 43 | 14.0% |
| Fairfax, MO | 695 | 43 | 14.0% |
| City | Population | Air Quality Index | National Avg. |
| Hollis Crossroads, AL | 695 | 38 | 24.0% |
| Elkhart, IA | 695 | 39 | 22.0% |
| Stanford, IL | 695 | 44 | 12.0% |
| Roachdale, IN | 695 | 54 | 8.0% |
| Magnolia, KY | 695 | 39 | 22.0% |
| Fairfax, MO | 695 | 43 | 14.0% |
Here are the best places to live in Missouri
10 Best cities in Missouri for employment
Top 10 cities in Missouri with the best education system
10 best cities to buy a new house in Missouri