Kingston, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 6.8 °C (low) to 15.3 °C (high). Annual precipitation averages 902 Millimeters. Kingston is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 2.5 °C | 8.3 °C | 132.08 mm |
| February | 2.5 °C | 9.6 °C | 82.04 mm |
| March | 3.7 °C | 11.8 °C | 92.96 mm |
| April | 5.3 °C | 14.4 °C | 61.98 mm |
| May | 8.1 °C | 17.9 °C | 52.83 mm |
| June | 10.4 °C | 20.3 °C | 42.67 mm |
| July | 12.1 °C | 23.3 °C | 21.34 mm |
| August | 12.3 °C | 23.8 °C | 24.64 mm |
| September | 10.5 °C | 20.7 °C | 38.35 mm |
| October | 7.4 °C | 15.4 °C | 84.07 mm |
| November | 4.4 °C | 10.7 °C | 133.86 mm |
| December | 2.4 °C | 7.8 °C | 135.13 mm |
| Annual | 6.8 °C | 15.3 °C | 901.95 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| 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 |