Duck Key, Florida has a Tropical Savanna (Wet and Dry Climate) climate (Köppen classification: Aw). Average annual temperatures range from 73.3 °F (low) to 82 °F (high). Annual precipitation averages 42.3 Inches. Duck Key is located in USDA Plant Hardiness Zone 11b.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 64.2 °F | 73.9 °F | 1.79 in. |
| February | 66.0 °F | 75.7 °F | 1.72 in. |
| March | 68.2 °F | 77.5 °F | 1.72 in. |
| April | 72.3 °F | 81.1 °F | 2.18 in. |
| May | 75.7 °F | 83.9 °F | 2.85 in. |
| June | 78.7 °F | 87.1 °F | 4.65 in. |
| July | 80.0 °F | 88.7 °F | 3.65 in. |
| August | 80.2 °F | 89.0 °F | 5.92 in. |
| September | 79.0 °F | 87.4 °F | 7.07 in. |
| October | 76.2 °F | 84.1 °F | 6.4 in. |
| November | 71.1 °F | 79.1 °F | 2.49 in. |
| December | 67.4 °F | 76.0 °F | 1.85 in. |
| Annual | 73.3 °F | 82 °F | 42.29 in. |
| Average First Frost Date | No Frost |
| Average Last Frost Date | |
| Average Days With Frost | Frost Free |
| Plant Hardiness Zone | Zone 11b : 45°F to 40°F |
| Plant Hardiness Zone - 2012 | Zone 11a : 40°F to 35°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Aw - Tropical Savanna (Wet and Dry Climate) |