Lake Stevens, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 6.1 °C (low) to 15.2 °C (high). Annual precipitation averages 1230.9 Millimeters. Lake Stevens 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 | 1.3 °C | 7.8 °C | 165.86 mm |
| February | 1.3 °C | 9.4 °C | 111.76 mm |
| March | 2.7 °C | 11.7 °C | 129.79 mm |
| April | 4.8 °C | 14.3 °C | 103.63 mm |
| May | 7.8 °C | 17.9 °C | 73.15 mm |
| June | 10.2 °C | 20.2 °C | 72.14 mm |
| July | 12.1 °C | 23.4 °C | 29.46 mm |
| August | 12.1 °C | 23.9 °C | 28.19 mm |
| September | 9.7 °C | 21.1 °C | 64.77 mm |
| October | 6.2 °C | 15.2 °C | 124.71 mm |
| November | 3.2 °C | 10.3 °C | 172.72 mm |
| December | 1.2 °C | 7.3 °C | 154.69 mm |
| Annual | 6.1 °C | 15.2 °C | 1230.87 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 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |