Duck Key, Florida has a Tropical Savanna (Wet and Dry Climate) climate (Köppen classification: Aw). Average annual temperatures range from 22.9 °C (low) to 27.8 °C (high). Annual precipitation averages 1074.2 Millimeters. Duck Key is located in USDA Plant Hardiness Zone 11b.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 17.9 °C | 23.3 °C | 45.47 mm |
| February | 18.9 °C | 24.3 °C | 43.69 mm |
| March | 20.1 °C | 25.3 °C | 43.69 mm |
| April | 22.4 °C | 27.3 °C | 55.37 mm |
| May | 24.3 °C | 28.8 °C | 72.39 mm |
| June | 25.9 °C | 30.6 °C | 118.11 mm |
| July | 26.7 °C | 31.5 °C | 92.71 mm |
| August | 26.8 °C | 31.7 °C | 150.37 mm |
| September | 26.1 °C | 30.8 °C | 179.58 mm |
| October | 24.6 °C | 28.9 °C | 162.56 mm |
| November | 21.7 °C | 26.2 °C | 63.25 mm |
| December | 19.7 °C | 24.4 °C | 46.99 mm |
| Annual | 22.9 °C | 27.8 °C | 1074.18 mm |
| Average First Frost Date | No Frost |
| Average Last Frost Date | |
| Average Days With Frost | Frost Free |
| Plant Hardiness Zone | Zone 11b : 7.2°C to 10°C |
| Plant Hardiness Zone - 2012 | Zone 11a : 4.4°C to 7.2°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Aw - Tropical Savanna (Wet and Dry Climate) |