Dauphin Island, Alabama has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 17.5 °C (low) to 23.3 °C (high). Annual precipitation averages 1567.7 Millimeters. Dauphin Island is located in USDA Plant Hardiness Zone 9b.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 7.7 °C | 14.7 °C | 135.38 mm |
| February | 9.2 °C | 16.2 °C | 116.84 mm |
| March | 12.8 °C | 19.1 °C | 135.89 mm |
| April | 17.1 °C | 22.6 °C | 124.46 mm |
| May | 21.6 °C | 26.5 °C | 113.54 mm |
| June | 24.9 °C | 29.3 °C | 143.51 mm |
| July | 25.7 °C | 30.5 °C | 172.21 mm |
| August | 25.8 °C | 30.6 °C | 153.16 mm |
| September | 23.9 °C | 29.1 °C | 140.97 mm |
| October | 18.7 °C | 24.9 °C | 95.25 mm |
| November | 12.8 °C | 19.9 °C | 105.41 mm |
| December | 9.3 °C | 16.2 °C | 131.06 mm |
| Annual | 17.5 °C | 23.3 °C | 1567.68 mm |
| Average First Frost Date | Frost Rare |
| Average Last Frost Date | |
| Average Days With Frost | Frost Rare |
| Plant Hardiness Zone | Zone 9b : -3.9°C to -1.1°C |
| Plant Hardiness Zone - 2012 | Zone 9a : -6.7°C to -3.9°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |