| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 24°F | 43°F | 32°F | 1.8" |
| February | 26°F | 45°F | 34°F | 1.6" |
| March | 37°F | 59°F | 47°F | 3.7" |
| April | 47°F | 70°F | 58°F | 5.3" |
| May | 56°F | 78°F | 67°F | 4.8" |
| June | 65°F | 88°F | 76°F | 4.4" |
| July | 68°F | 90°F | 79°F | 3.9" |
| August | 66°F | 89°F | 77°F | 3.1" |
| September | 58°F | 82°F | 69°F | 4.2" |
| October | 47°F | 71°F | 58°F | 3.1" |
| November | 36°F | 58°F | 46°F | 2.8" |
| December | 29°F | 45°F | 36°F | 3.1" |
| Index | Old North Saint Louis | St. Louis | Missouri |
| Air quality index | 54 | 54 | 97 |
| Pollution index | 8,473,050 | 8,473,050 | 1,630,255 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 134 |
| Days with moderate air quality | 221 |
| Days w/ poor A.Q. for sensitive groups | 8 |
| Days with unhealthy air quality | 2 |
| Pollutant | Total |
| Arsenic | 0.020% |
| Benzene | 0.070% |
| Carbon Tetrachloride | 0.020% |
| Lead | 0.010% |
| Mercury | 0.010% |
| City | Population | Air Quality Index | National Avg. |
| Old Jamestown, MO | 19,602 | 54 | 8.0% |
| Maryville, IL | 7,962 | 54 | 8.0% |
| Wood River, IL | 10,149 | 54 | 8.0% |
| Caseyville, IL | 4,203 | 54 | 8.0% |
| Clayton, MO | 16,763 | 54 | 8.0% |
| St. Louis, MO | 304,709 | 54 | 8.0% |
| City | Population | Air Quality Index | National Avg. |
| St. Paul, MN | 305,877 | 46 | 8.0% |
| Cincinnati, OH | 302,687 | 54 | 8.0% |
| Pittsburgh, PA | 301,286 | 56 | 12.0% |
| Henderson, NV | 309,955 | 54 | 8.0% |
| Stockton, CA | 311,103 | 45 | 10.0% |
| St. Louis, MO | 304,709 | 54 | 8.0% |
Here are the best places to live in Missouri
Safest States In The US
Check out the 10 most dangerous cities in Missouri
Check out the 10 safest cities in Missouri