Seattle, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 44.9 °F (low) to 60.4 °F (high). Annual precipitation averages 38.7 Inches. Seattle is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Mar. 11 - Mar. 20 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 36.6 °F | 47.1 °F | 5.37 in. |
| February | 36.8 °F | 49.7 °F | 3.69 in. |
| March | 38.9 °F | 53.6 °F | 4.15 in. |
| April | 42.2 °F | 58.6 °F | 3.01 in. |
| May | 47.4 °F | 65.5 °F | 2.0 in. |
| June | 51.8 °F | 69.7 °F | 1.67 in. |
| July | 55.2 °F | 75.7 °F | 0.77 in. |
| August | 55.5 °F | 76.4 °F | 0.94 in. |
| September | 52.0 °F | 70.8 °F | 1.6 in. |
| October | 46.0 °F | 60.3 °F | 3.81 in. |
| November | 40.2 °F | 51.5 °F | 5.86 in. |
| December | 36.4 °F | 46.2 °F | 5.83 in. |
| Annual | 44.9 °F | 60.4 °F | 38.7 in. |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 11 - Mar. 20 |
| Average Days With Frost | 20-30 Days |
| Plant Hardiness Zone | Zone 9a : 20°F to 25°F |
| Plant Hardiness Zone - 2012 | Zone 8b : 15°F to 20°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |