Hartwell, Georgia has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 51 °F (low) to 72.4 °F (high). Annual precipitation averages 51.3 Inches. Hartwell is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 11 - Mar. 20 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 32.6 °F | 53.3 °F | 4.38 in. |
| February | 35.3 °F | 57.1 °F | 4.46 in. |
| March | 41.4 °F | 64.6 °F | 4.53 in. |
| April | 49.3 °F | 73.0 °F | 3.72 in. |
| May | 58.3 °F | 80.1 °F | 3.85 in. |
| June | 66.3 °F | 86.8 °F | 4.35 in. |
| July | 69.8 °F | 90.0 °F | 4.35 in. |
| August | 69.0 °F | 88.1 °F | 4.56 in. |
| September | 63.3 °F | 82.8 °F | 4.45 in. |
| October | 51.3 °F | 73.2 °F | 3.7 in. |
| November | 40.5 °F | 63.8 °F | 3.99 in. |
| December | 35.3 °F | 55.7 °F | 5.0 in. |
| Annual | 51 °F | 72.4 °F | 51.34 in. |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 11 - Mar. 20 |
| Average Days With Frost | 40-50 Days |
| Plant Hardiness Zone | Zone 8b : 15°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 8a : 10°F to 15°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |