| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 30°F | 50°F | 39°F | 5.2" |
| February | 32°F | 53°F | 41°F | 4.8" |
| March | 41°F | 65°F | 51°F | 5.1" |
| April | 49°F | 75°F | 61°F | 6.6" |
| May | 57°F | 82°F | 69°F | 7.2" |
| June | 66°F | 91°F | 78°F | 4.1" |
| July | 69°F | 93°F | 80°F | 5.1" |
| August | 68°F | 93°F | 80°F | 5.5" |
| September | 61°F | 86°F | 72°F | 5.9" |
| October | 49°F | 75°F | 60°F | 5.5" |
| November | 38°F | 63°F | 49°F | 6.2" |
| December | 33°F | 54°F | 43°F | 6.9" |
| Index | Lebanon | Tennessee | National |
| Air quality index | 45 | 76 | 42 |
| Pollution index | 1,764,100 | 2,454,916 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 229 |
| Days with moderate air quality | 135 |
| Days w/ poor A.Q. for sensitive groups | 1 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.001% |
| Benzene | 0.030% |
| Carbon Tetrachloride | 0.004% |
| Lead | 0.030% |
| Mercury | 0.010% |
| City | Population | Air Quality Index | National Avg. |
| Alexandria, TN | 1,022 | 25 | 50.0% |
| Watertown, TN | 1,741 | 25 | 50.0% |
| Castalian Springs, TN | 405 | 45 | 10.0% |
| Rural Hill, TN | 2,612 | 45 | 10.0% |
| Gallatin, TN | 41,372 | 45 | 10.0% |
| Lebanon, TN | 36,126 | 45 | 10.0% |
| City | Population | Air Quality Index | National Avg. |
| Bell, CA | 36,113 | 72 | 44.0% |
| Monroe, NC | 36,140 | 49 | 2.0% |
| Gadsden, AL | 36,146 | 43 | 14.0% |
| Westmont, CA | 36,088 | 72 | 44.0% |
| Post Falls, ID | 36,171 | 43 | 14.0% |
| Lebanon, TN | 36,126 | 45 | 10.0% |