Yacolt, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 5.2 °C (low) to 16.3 °C (high). Annual precipitation averages 1835.9 Millimeters. Yacolt is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 0.4 °C | 6.7 °C | 255.78 mm |
| February | 0.6 °C | 8.9 °C | 189.48 mm |
| March | 1.8 °C | 11.8 °C | 206.25 mm |
| April | 3.7 °C | 15.3 °C | 153.92 mm |
| May | 6.7 °C | 19.9 °C | 112.01 mm |
| June | 9.1 °C | 21.9 °C | 77.47 mm |
| July | 11.2 °C | 26.8 °C | 21.34 mm |
| August | 11.2 °C | 27.2 °C | 27.43 mm |
| September | 8.8 °C | 23.9 °C | 76.45 mm |
| October | 5.6 °C | 16.8 °C | 167.39 mm |
| November | 2.6 °C | 10.2 °C | 263.65 mm |
| December | 0.3 °C | 6.3 °C | 284.73 mm |
| Annual | 5.2 °C | 16.3 °C | 1835.9 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 8b : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8a : -12.2°C to -9.4°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |