Keyport, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 6.8 °C (low) to 16 °C (high). Annual precipitation averages 984 Millimeters. Keyport is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 2.4 °C | 8.6 °C | 150.88 mm |
| February | 2.3 °C | 9.9 °C | 84.07 mm |
| March | 3.5 °C | 12.1 °C | 104.39 mm |
| April | 5.3 °C | 15.1 °C | 69.85 mm |
| May | 8.1 °C | 18.7 °C | 47.75 mm |
| June | 10.6 °C | 20.9 °C | 43.69 mm |
| July | 12.4 °C | 24.5 °C | 21.59 mm |
| August | 12.4 °C | 25 °C | 25.15 mm |
| September | 10.6 °C | 21.9 °C | 44.7 mm |
| October | 7.3 °C | 15.9 °C | 90.93 mm |
| November | 4.2 °C | 10.9 °C | 147.07 mm |
| December | 2.3 °C | 8.1 °C | 153.92 mm |
| Annual | 6.8 °C | 16 °C | 983.99 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 40-50 Days |
| Plant Hardiness Zone | Zone 9a : -6.7°C to -3.9°C |
| Plant Hardiness Zone - 2012 | Zone 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |