Keystone Heights, Florida has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 14.6 °C (low) to 27 °C (high). Annual precipitation averages 1355.9 Millimeters. Keystone Heights is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Feb. 21 - Feb. 29 through the first frost around Dec. 1 - Dec. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 6.1 °C | 19.4 °C | 86.61 mm |
| February | 7.5 °C | 21.3 °C | 73.41 mm |
| March | 10 °C | 24.4 °C | 85.6 mm |
| April | 13.3 °C | 27.3 °C | 67.82 mm |
| May | 17.2 °C | 30.7 °C | 104.65 mm |
| June | 21 °C | 32.4 °C | 205.23 mm |
| July | 22.2 °C | 33.1 °C | 184.4 mm |
| August | 22.2 °C | 32.7 °C | 168.91 mm |
| September | 20.8 °C | 31.1 °C | 169.16 mm |
| October | 16.2 °C | 27.7 °C | 86.87 mm |
| November | 10.8 °C | 23.7 °C | 52.83 mm |
| December | 7.8 °C | 20.7 °C | 70.36 mm |
| Annual | 14.6 °C | 27 °C | 1355.85 mm |
| Average First Frost Date | Dec. 1 - Dec. 10 |
| Average Last Frost Date | Feb. 21 - Feb. 29 |
| Average Days With Frost | 10-20 Days |
| Plant Hardiness Zone | Zone 9a : -6.7°C to -3.9°C |
| Plant Hardiness Zone - 2012 | Zone 9a : -6.7°C to -3.9°C |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |