| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 18°F | 40°F | 27°F | 0.6" |
| February | 20°F | 43°F | 31°F | 1.1" |
| March | 34°F | 58°F | 44°F | 2.3" |
| April | 44°F | 68°F | 55°F | 4.1" |
| May | 54°F | 77°F | 65°F | 5.1" |
| June | 65°F | 87°F | 75°F | 5.2" |
| July | 68°F | 89°F | 78°F | 3.6" |
| August | 65°F | 87°F | 75°F | 4.1" |
| September | 56°F | 81°F | 68°F | 3.7" |
| October | 44°F | 69°F | 55°F | 3.6" |
| November | 32°F | 56°F | 43°F | 1.7" |
| December | 21°F | 41°F | 30°F | 1.6" |
| Index | Maryville | Missouri | National |
| Air quality index | 43 | 97 | 42 |
| Pollution index | 543,130 | 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 | 0.002% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.003% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Clearmont, MO | 161 | 43 | 14.0% |
| Pickering, MO | 170 | 43 | 14.0% |
| Guilford, MO | 94 | 43 | 14.0% |
| Clyde, MO | 45 | 43 | 14.0% |
| Maitland, MO | 250 | 43 | 14.0% |
| Maryville, MO | 11,641 | 43 | 14.0% |
| City | Population | Air Quality Index | National Avg. |
| Manor, TX | 11,643 | 44 | 12.0% |
| Mango, FL | 11,638 | 43 | 14.0% |
| Lethbridge County, AB | 11,635 | n/a | |
| Four Corners, TX | 11,634 | 52 | 4.0% |
| Largo, MD | 11,633 | 47 | 6.0% |
| Maryville, MO | 11,641 | 43 | 14.0% |
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