Forsyth, Georgia has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 10.5 °C (low) to 23.9 °C (high). Annual precipitation averages 1262.6 Millimeters. Forsyth is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 0.7 °C | 13.7 °C | 112.52 mm |
| February | 2.3 °C | 15.8 °C | 120.9 mm |
| March | 5.4 °C | 20.1 °C | 124.46 mm |
| April | 9.4 °C | 24.4 °C | 102.62 mm |
| May | 14.4 °C | 28.3 °C | 73.91 mm |
| June | 18.7 °C | 31.2 °C | 105.92 mm |
| July | 20.7 °C | 32.8 °C | 131.32 mm |
| August | 20.3 °C | 32.1 °C | 111 mm |
| September | 16.9 °C | 29.4 °C | 92.2 mm |
| October | 10.8 °C | 24.6 °C | 76.45 mm |
| November | 4.8 °C | 19.2 °C | 93.73 mm |
| December | 2 °C | 14.8 °C | 117.6 mm |
| Annual | 10.5 °C | 23.9 °C | 1262.63 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 8b : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8a : -12.2°C to -9.4°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |