Oakville, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 41.9 °F (low) to 61.8 °F (high). Annual precipitation averages 57.9 Inches. Oakville 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 35.0 °F | 47.1 °F | 9.08 in. |
| February | 34.4 °F | 50.3 °F | 5.99 in. |
| March | 36.2 °F | 54.7 °F | 6.19 in. |
| April | 38.9 °F | 60.7 °F | 4.53 in. |
| May | 44.2 °F | 67.3 °F | 2.62 in. |
| June | 48.4 °F | 70.9 °F | 2.02 in. |
| July | 52.0 °F | 77.7 °F | 0.58 in. |
| August | 52.0 °F | 78.5 °F | 1.02 in. |
| September | 48.0 °F | 73.4 °F | 2.08 in. |
| October | 42.3 °F | 62.4 °F | 5.31 in. |
| November | 37.2 °F | 51.9 °F | 9.37 in. |
| December | 34.6 °F | 46.1 °F | 9.11 in. |
| Annual | 41.9 °F | 61.8 °F | 57.9 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 8b : 15°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 8a : 10°F to 15°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |