Snohomish, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 6.1 °C (low) to 15.5 °C (high). Annual precipitation averages 1124.2 Millimeters. Snohomish 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 | 1.6 °C | 8.1 °C | 139.7 mm |
| February | 1.6 °C | 9.8 °C | 99.82 mm |
| March | 2.9 °C | 12.1 °C | 119.13 mm |
| April | 4.9 °C | 14.6 °C | 96.01 mm |
| May | 7.8 °C | 18.3 °C | 71.88 mm |
| June | 10.2 °C | 20.4 °C | 63.25 mm |
| July | 11.9 °C | 23.7 °C | 26.92 mm |
| August | 11.8 °C | 24.3 °C | 27.69 mm |
| September | 9.7 °C | 21.3 °C | 57.66 mm |
| October | 6.4 °C | 15.4 °C | 107.7 mm |
| November | 3.4 °C | 10.7 °C | 163.32 mm |
| December | 1.4 °C | 7.6 °C | 151.13 mm |
| Annual | 6.1 °C | 15.5 °C | 1124.21 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 40-50 Days |
| Plant Hardiness Zone | Zone 8b : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |