Lake Stevens, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 42.9 °F (low) to 59.4 °F (high). Annual precipitation averages 48.5 Inches. 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 | 34.4 °F | 46.1 °F | 6.53 in. |
| February | 34.4 °F | 49.0 °F | 4.4 in. |
| March | 36.9 °F | 53.0 °F | 5.11 in. |
| April | 40.7 °F | 57.7 °F | 4.08 in. |
| May | 46.1 °F | 64.3 °F | 2.88 in. |
| June | 50.3 °F | 68.3 °F | 2.84 in. |
| July | 53.7 °F | 74.2 °F | 1.16 in. |
| August | 53.8 °F | 75.1 °F | 1.11 in. |
| September | 49.5 °F | 69.9 °F | 2.55 in. |
| October | 43.2 °F | 59.3 °F | 4.91 in. |
| November | 37.7 °F | 50.5 °F | 6.8 in. |
| December | 34.2 °F | 45.2 °F | 6.09 in. |
| Annual | 42.9 °F | 59.4 °F | 48.46 in. |
| 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 : 15°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 8b : 15°F to 20°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |