Peaceful Valley, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 5.2 °C (low) to 14.5 °C (high). Annual precipitation averages 1702.6 Millimeters. Peaceful Valley is located in USDA Plant Hardiness Zone 8a. 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 | -0.4 °C | 5.4 °C | 231.14 mm |
| February | 0.3 °C | 7.6 °C | 136.65 mm |
| March | 1.7 °C | 10.3 °C | 177.04 mm |
| April | 3.9 °C | 14 °C | 125.22 mm |
| May | 7.1 °C | 18 °C | 104.39 mm |
| June | 9.8 °C | 20.4 °C | 82.8 mm |
| July | 11.8 °C | 24.2 °C | 49.02 mm |
| August | 11.8 °C | 24.7 °C | 50.04 mm |
| September | 9 °C | 20.8 °C | 89.92 mm |
| October | 5.6 °C | 14.6 °C | 177.04 mm |
| November | 2.1 °C | 8.6 °C | 265.18 mm |
| December | -0.4 °C | 5.1 °C | 214.12 mm |
| Annual | 5.2 °C | 14.5 °C | 1702.56 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 8a : -12.2°C to -9.4°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 |