Harrison, Georgia has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 52.9 °F (low) to 75.9 °F (high). Annual precipitation averages 47.8 Inches. Harrison 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. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 35.4 °F | 58.0 °F | 4.38 in. |
| February | 37.8 °F | 61.6 °F | 4.29 in. |
| March | 43.9 °F | 69.0 °F | 4.44 in. |
| April | 50.9 °F | 76.3 °F | 3.45 in. |
| May | 59.9 °F | 83.4 °F | 2.99 in. |
| June | 67.6 °F | 89.0 °F | 4.74 in. |
| July | 70.9 °F | 92.2 °F | 4.6 in. |
| August | 69.9 °F | 90.3 °F | 4.92 in. |
| September | 64.5 °F | 85.8 °F | 3.85 in. |
| October | 53.7 °F | 77.0 °F | 2.78 in. |
| November | 42.8 °F | 67.6 °F | 2.99 in. |
| December | 37.3 °F | 60.0 °F | 4.39 in. |
| Annual | 52.9 °F | 75.9 °F | 47.82 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| 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 | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |