| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 17°F | 37°F | 26°F | 1.8" |
| February | 19°F | 40°F | 29°F | 1.9" |
| March | 32°F | 55°F | 42°F | 3.1" |
| April | 42°F | 66°F | 53°F | 4.7" |
| May | 52°F | 74°F | 62°F | 4.8" |
| June | 62°F | 84°F | 72°F | 6.9" |
| July | 65°F | 87°F | 76°F | 4.3" |
| August | 63°F | 85°F | 73°F | 4.3" |
| September | 55°F | 79°F | 66°F | 4.1" |
| October | 44°F | 66°F | 54°F | 4.0" |
| November | 33°F | 54°F | 42°F | 2.6" |
| December | 22°F | 39°F | 30°F | 1.9" |
| Index | Callao | Missouri | National |
| Air quality index | 38 | 97 | 42 |
| Pollution index | 637,848 | 1,630,255 | 2,726,193 |
| Measurement | Total |
| Days measured | 245 |
| Days with good air quality | 239 |
| Days with moderate air quality | 6 |
| 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 | 0.001% |
| Lead | 0.001% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Macon, MO | 5,357 | 38 | 24.0% |
| Ethel, MO | 54 | 38 | 24.0% |
| Bevier, MO | 671 | 38 | 24.0% |
| New Cambria, MO | 114 | 38 | 24.0% |
| Jacksonville, MO | 134 | 38 | 24.0% |
| Callao, MO | 319 | 38 | 24.0% |
| City | Population | Air Quality Index | National Avg. |
| Horn Hill, AL | 319 | 35 | 30.0% |
| Cash, AR | 319 | 45 | 10.0% |
| Brooker, FL | 319 | 35 | 30.0% |
| Bronwood, GA | 319 | 39 | 22.0% |
| Taylorsville, GA | 319 | 44 | 12.0% |
| Callao, MO | 319 | 38 | 24.0% |
Here are the best places to live in Missouri
Check out the 10 most dangerous cities in Missouri
These are the largest cities in Missouri
Most Dangerous Cities In The US