Stanwood, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 42.5 °F (low) to 58.5 °F (high). Annual precipitation averages 33.1 Inches. Stanwood is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 35.1 °F | 46.4 °F | 3.96 in. |
| February | 34.8 °F | 48.2 °F | 2.96 in. |
| March | 37.3 °F | 52.4 °F | 3.65 in. |
| April | 40.6 °F | 57.0 °F | 2.82 in. |
| May | 45.3 °F | 63.0 °F | 2.42 in. |
| June | 49.5 °F | 67.1 °F | 1.47 in. |
| July | 51.7 °F | 72.1 °F | 1.01 in. |
| August | 51.7 °F | 73.1 °F | 1.08 in. |
| September | 48.2 °F | 68.0 °F | 1.84 in. |
| October | 42.7 °F | 58.8 °F | 3.02 in. |
| November | 38.3 °F | 51.0 °F | 4.76 in. |
| December | 34.8 °F | 45.3 °F | 4.11 in. |
| Annual | 42.5 °F | 58.5 °F | 33.1 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 40-50 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 |