Washougal, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 7.2 °C (low) to 17.3 °C (high). Annual precipitation averages 1353.8 Millimeters. Washougal 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 | 2.3 °C | 8 °C | 182.63 mm |
| February | 2.6 °C | 10.2 °C | 126.24 mm |
| March | 3.8 °C | 13.2 °C | 152.91 mm |
| April | 5.8 °C | 16.2 °C | 114.81 mm |
| May | 8.7 °C | 20.2 °C | 91.69 mm |
| June | 11.1 °C | 22.9 °C | 72.64 mm |
| July | 13.3 °C | 27.3 °C | 20.83 mm |
| August | 13.3 °C | 27.7 °C | 16.26 mm |
| September | 10.9 °C | 24.2 °C | 55.37 mm |
| October | 7.7 °C | 17.7 °C | 127 mm |
| November | 4.7 °C | 11.6 °C | 195.33 mm |
| December | 2.2 °C | 7.8 °C | 198.12 mm |
| Annual | 7.2 °C | 17.3 °C | 1353.83 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 30-40 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 | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |