| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 34°F | 49°F | 41°F | 8.3" |
| February | 31°F | 49°F | 39°F | 5.6" |
| March | 42°F | 65°F | 52°F | 2.7" |
| April | 48°F | 70°F | 58°F | 6.3" |
| May | 56°F | 80°F | 68°F | 5.2" |
| June | 65°F | 87°F | 75°F | 4.9" |
| July | 69°F | 89°F | 78°F | 5.1" |
| August | 71°F | 94°F | 82°F | 12.1" |
| September | 63°F | 85°F | 73°F | 5.3" |
| October | 52°F | 74°F | 62°F | 16.9" |
| November | 40°F | 62°F | 50°F | 4.5" |
| December | 32°F | 49°F | 39°F | 7.8" |
| Index | Princeton | Kentucky | National |
| Air quality index | 44 | 45 | 42 |
| Pollution index | 5,501,360 | 1,369,131 | 2,726,193 |
| Measurement | Total |
| Days measured | 364 |
| Days with good air quality | 261 |
| Days with moderate air quality | 103 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.010% |
| Benzene | 0.130% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.020% |
| Mercury | 0.800% |
| City | Population | Air Quality Index | National Avg. |
| Cerulean, KY | 507 | 40 | 20.0% |
| Dawson Springs, KY | 2,755 | 40 | 20.0% |
| Crayne, KY | 286 | 44 | 12.0% |
| Eddyville, KY | 2,619 | 44 | 12.0% |
| Fredonia, KY | 481 | 44 | 12.0% |
| Princeton, KY | 6,227 | 44 | 12.0% |
| City | Population | Air Quality Index | National Avg. |
| Okanagan-Similkameen D, BC | 6,227 | n/a | |
| Mascotte, FL | 6,228 | 36 | 28.0% |
| Laurence Harbor, NJ | 6,228 | 51 | 2.0% |
| Tequesta, FL | 6,225 | 36 | 28.0% |
| Watchung, NJ | 6,225 | 51 | 2.0% |
| Princeton, KY | 6,227 | 44 | 12.0% |