Ferndale, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 6.2 °C (low) to 14.8 °C (high). Annual precipitation averages 1003 Millimeters. Ferndale is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 1.4 °C | 7.3 °C | 138.43 mm |
| February | 1.7 °C | 8.7 °C | 86.87 mm |
| March | 3.1 °C | 10.9 °C | 104.39 mm |
| April | 5.1 °C | 14.3 °C | 75.95 mm |
| May | 7.9 °C | 17.7 °C | 60.96 mm |
| June | 10.4 °C | 20.1 °C | 45.21 mm |
| July | 12 °C | 22.8 °C | 27.43 mm |
| August | 11.9 °C | 23.1 °C | 29.46 mm |
| September | 9.5 °C | 20.2 °C | 48.01 mm |
| October | 6.4 °C | 15.1 °C | 109.47 mm |
| November | 3.6 °C | 10.1 °C | 150.88 mm |
| December | 1.3 °C | 7 °C | 125.98 mm |
| Annual | 6.2 °C | 14.8 °C | 1003.04 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 8b : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8a : -12.2°C to -9.4°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |