| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 24°F | 43°F | 33°F | 3.7" |
| February | 26°F | 46°F | 35°F | 3.3" |
| March | 36°F | 59°F | 47°F | 4.3" |
| April | 45°F | 70°F | 57°F | 5.9" |
| May | 54°F | 77°F | 65°F | 5.1" |
| June | 62°F | 85°F | 73°F | 4.7" |
| July | 66°F | 87°F | 76°F | 6.3" |
| August | 64°F | 87°F | 75°F | 2.8" |
| September | 57°F | 81°F | 69°F | 3.8" |
| October | 45°F | 70°F | 57°F | 4.0" |
| November | 35°F | 58°F | 45°F | 3.1" |
| December | 29°F | 48°F | 38°F | 4.7" |
| Index | Smithfield | Kentucky | National |
| Air quality index | 49 | 45 | 42 |
| Pollution index | 10,162,700 | 1,369,131 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 195 |
| Days with moderate air quality | 166 |
| Days w/ poor A.Q. for sensitive groups | 4 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.010% |
| Benzene | 0.060% |
| Carbon Tetrachloride | 0.010% |
| Lead | 0.050% |
| Mercury | 0.140% |
| City | Population | Air Quality Index | National Avg. |
| Woodland Hills, KY | 664 | 49 | 2.0% |
| La Grange, KY | 8,938 | 49 | 2.0% |
| New Castle, KY | 1,050 | 49 | 2.0% |
| Campbellsburg, KY | 1,018 | 49 | 2.0% |
| Buckner, KY | 5,640 | 49 | 2.0% |
| Smithfield, KY | 213 | 49 | 2.0% |
| City | Population | Air Quality Index | National Avg. |
| Nanwalek, AK | 213 | 31 | 38.0% |
| Sweet Water, AL | 213 | 36 | 28.0% |
| Ruth, CA | 213 | 42 | 16.0% |
| Westside, CA | 213 | 72 | 44.0% |
| Rye, CO | 213 | 20 | 60.0% |
| Smithfield, KY | 213 | 49 | 2.0% |
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