| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 24°F | 45°F | 33°F | 2.4" |
| February | 25°F | 48°F | 35°F | 2.2" |
| March | 37°F | 61°F | 48°F | 3.6" |
| April | 47°F | 72°F | 59°F | 5.4" |
| May | 57°F | 80°F | 68°F | 4.6" |
| June | 67°F | 89°F | 78°F | 5.2" |
| July | 70°F | 92°F | 81°F | 4.2" |
| August | 69°F | 91°F | 79°F | 3.6" |
| September | 61°F | 84°F | 72°F | 4.3" |
| October | 48°F | 72°F | 60°F | 3.4" |
| November | 37°F | 60°F | 48°F | 3.4" |
| December | 27°F | 47°F | 37°F | 3.5" |
| Index | Hanley Hills | Missouri | National |
| Air quality index | 54 | 97 | 42 |
| Pollution index | 8,473,050 | 1,630,255 | 2,726,193 |
| 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. |
| Florissant, MO | 51,220 | 54 | 8.0% |
| East Alton, IL | 6,021 | 54 | 8.0% |
| South Roxana, IL | 2,304 | 54 | 8.0% |
| Brooklyn, IL | 428 | 54 | 8.0% |
| Concord, MO | 18,521 | 54 | 8.0% |
| Hanley Hills, MO | 1,853 | 54 | 8.0% |
| City | Population | Air Quality Index | National Avg. |
| Kingstown, MD | 1,853 | 42 | 16.0% |
| Hemby Bridge, NC | 1,853 | 49 | 2.0% |
| Smoke Rise, AL | 1,852 | 53 | 6.0% |
| Westover, AL | 1,854 | 53 | 6.0% |
| Killian, LA | 1,852 | 30 | 40.0% |
| Hanley Hills, MO | 1,853 | 54 | 8.0% |
Here are the best places to live in Missouri
Most Dangerous Cities In The US
Check out the 10 most dangerous cities in Missouri
These are the 10 cheapest cities in Missouri