Fellsmere, Florida has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 17.4 °C (low) to 28.3 °C (high). Annual precipitation averages 1458.2 Millimeters. Fellsmere is located in USDA Plant Hardiness Zone 10a.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 10.4 °C | 22.7 °C | 67.56 mm |
| February | 11.7 °C | 24.2 °C | 64.01 mm |
| March | 13.7 °C | 25.9 °C | 79.25 mm |
| April | 16.5 °C | 28.1 °C | 67.82 mm |
| May | 19.3 °C | 30.6 °C | 107.7 mm |
| June | 21.7 °C | 31.8 °C | 199.64 mm |
| July | 22.5 °C | 32.7 °C | 177.29 mm |
| August | 22.9 °C | 32.8 °C | 223.27 mm |
| September | 22.3 °C | 31.8 °C | 195.33 mm |
| October | 20 °C | 29.3 °C | 139.7 mm |
| November | 15.2 °C | 26.2 °C | 73.15 mm |
| December | 12.5 °C | 23.9 °C | 63.5 mm |
| Annual | 17.4 °C | 28.3 °C | 1458.22 mm |
| Average First Frost Date | Frost Rare |
| Average Last Frost Date | |
| Average Days With Frost | Frost Rare |
| Plant Hardiness Zone | Zone 10a : -1.1°C to 1.7°C |
| Plant Hardiness Zone - 2012 | Zone 9b : -3.9°C to -1.1°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |