Shelton, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 6 °C (low) to 16 °C (high). Annual precipitation averages 1582.7 Millimeters. Shelton 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 Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 1.8 °C | 8.2 °C | 253.75 mm |
| February | 1.6 °C | 9.7 °C | 160.02 mm |
| March | 2.7 °C | 12.2 °C | 170.43 mm |
| April | 4.3 °C | 15.3 °C | 116.33 mm |
| May | 7.4 °C | 19.1 °C | 67.56 mm |
| June | 9.9 °C | 21.3 °C | 41.66 mm |
| July | 11.8 °C | 24.8 °C | 15.24 mm |
| August | 11.8 °C | 25.3 °C | 29.72 mm |
| September | 9.5 °C | 22.2 °C | 55.88 mm |
| October | 6.2 °C | 15.8 °C | 157.23 mm |
| November | 3.3 °C | 10.7 °C | 257.05 mm |
| December | 1.5 °C | 7.6 °C | 257.81 mm |
| Annual | 6 °C | 16 °C | 1582.68 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 8b : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |