| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 38°F | 60°F | 47°F | 2.6" |
| February | 35°F | 59°F | 45°F | 4.9" |
| March | 43°F | 70°F | 54°F | 6.6" |
| April | 49°F | 76°F | 61°F | 4.9" |
| May | 58°F | 81°F | 68°F | 1.8" |
| June | 69°F | 88°F | 76°F | 9.3" |
| July | 71°F | 90°F | 79°F | 6.4" |
| August | 72°F | 94°F | 81°F | 4.9" |
| September | 66°F | 90°F | 76°F | 1.6" |
| October | 56°F | 80°F | 66°F | 9.2" |
| November | 42°F | 69°F | 54°F | 2.1" |
| December | 37°F | 61°F | 47°F | 9.8" |
| Index | Lydia | South Carolina | National |
| Air quality index | 40 | 37 | 42 |
| Pollution index | 1,817,360 | 3,620,438 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 288 |
| Days with moderate air quality | 77 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.010% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.020% |
| Mercury | 0.001% |
| City | Population | Air Quality Index | National Avg. |
| Lamar, SC | 1,156 | 40 | 20.0% |
| Bishopville, SC | 3,141 | 40 | 20.0% |
| North Hartsville, SC | 2,033 | 40 | 20.0% |
| McBee, SC | 1,011 | 40 | 20.0% |
| Timmonsville, SC | 2,540 | 40 | 20.0% |
| Lydia, SC | 433 | 40 | 20.0% |
| City | Population | Air Quality Index | National Avg. |
| Noatak, AK | 433 | 38 | 24.0% |
| Elkmont, AL | 433 | 44 | 12.0% |
| Vina, AL | 433 | 37 | 26.0% |
| Albion, ID | 433 | 20 | 60.0% |
| Versailles, IL | 433 | 41 | 18.0% |
| Lydia, SC | 433 | 40 | 20.0% |