| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 24°F | 43°F | 32°F | 2.5" |
| February | 26°F | 45°F | 34°F | 2.5" |
| March | 36°F | 58°F | 45°F | 4.3" |
| April | 46°F | 69°F | 57°F | 7.2" |
| May | 55°F | 76°F | 65°F | 6.3" |
| June | 64°F | 87°F | 75°F | 5.5" |
| July | 66°F | 90°F | 77°F | 10.4" |
| August | 63°F | 87°F | 75°F | 6.8" |
| September | 58°F | 85°F | 71°F | 6.4" |
| October | 49°F | 72°F | 59°F | 7.2" |
| November | 36°F | 57°F | 45°F | 7.9" |
| December | 29°F | 45°F | 36°F | 7.3" |
| Index | Huntsville | Missouri | National |
| Air quality index | 38 | 97 | 42 |
| Pollution index | 510,770 | 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 | 0.000% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Excello, MO | 29 | 38 | 24.0% |
| Armstrong, MO | 262 | 38 | 24.0% |
| Cairo, MO | 230 | 38 | 24.0% |
| Clifton Hill, MO | 76 | 38 | 24.0% |
| Clark, MO | 252 | 38 | 24.0% |
| Huntsville, MO | 1,820 | 38 | 24.0% |
| City | Population | Air Quality Index | National Avg. |
| Burnham, PA | 1,820 | 44 | 12.0% |
| Canton, PA | 1,820 | 36 | 28.0% |
| Perry Park, CO | 1,821 | 45 | 10.0% |
| Carrier Mills, IL | 1,819 | 44 | 12.0% |
| New Union, TN | 1,819 | 25 | 50.0% |
| Huntsville, MO | 1,820 | 38 | 24.0% |
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