| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 27°F | 44°F | 34°F | 2.9" |
| February | 28°F | 46°F | 36°F | 2.9" |
| March | 39°F | 60°F | 49°F | 4.7" |
| April | 49°F | 72°F | 60°F | 5.9" |
| May | 58°F | 79°F | 68°F | 4.9" |
| June | 67°F | 88°F | 77°F | 4.9" |
| July | 69°F | 89°F | 79°F | 5.6" |
| August | 68°F | 89°F | 78°F | 3.2" |
| September | 60°F | 83°F | 71°F | 4.9" |
| October | 48°F | 71°F | 59°F | 4.4" |
| November | 38°F | 59°F | 47°F | 3.6" |
| December | 32°F | 48°F | 39°F | 4.4" |
| Index | Mortons Gap | Kentucky | National |
| Air quality index | 43 | 45 | 42 |
| Pollution index | 768,150 | 1,369,131 | 2,726,193 |
| Measurement | Total |
| Days measured | 364 |
| Days with good air quality | 276 |
| Days with moderate air quality | 87 |
| Days w/ poor A.Q. for sensitive groups | 1 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.000% |
| Benzene | 0.010% |
| Carbon Tetrachloride | 0.005% |
| Lead | 0.003% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| St. Charles, KY | 312 | 40 | 20.0% |
| Dawson Springs, KY | 2,755 | 40 | 20.0% |
| White Plains, KY | 974 | 40 | 20.0% |
| Crofton, KY | 443 | 40 | 20.0% |
| Nortonville, KY | 1,020 | 40 | 20.0% |
| Mortons Gap, KY | 1,090 | 43 | 14.0% |
| City | Population | Air Quality Index | National Avg. |
| Skyline, AL | 1,090 | 44 | 12.0% |
| Young Harris, GA | 1,090 | 37 | 26.0% |
| Lawton, IA | 1,090 | 35 | 30.0% |
| Silver Lake, IN | 1,090 | 37 | 26.0% |
| Utica, NE | 1,090 | 31 | 38.0% |
| Mortons Gap, KY | 1,090 | 43 | 14.0% |