Oakville, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 5.5 °C (low) to 16.5 °C (high). Annual precipitation averages 1470.7 Millimeters. 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 | 1.7 °C | 8.4 °C | 230.63 mm |
| February | 1.3 °C | 10.2 °C | 152.15 mm |
| March | 2.3 °C | 12.6 °C | 157.23 mm |
| April | 3.8 °C | 15.9 °C | 115.06 mm |
| May | 6.8 °C | 19.6 °C | 66.55 mm |
| June | 9.1 °C | 21.6 °C | 51.31 mm |
| July | 11.1 °C | 25.4 °C | 14.73 mm |
| August | 11.1 °C | 25.8 °C | 25.91 mm |
| September | 8.9 °C | 23 °C | 52.83 mm |
| October | 5.7 °C | 16.9 °C | 134.87 mm |
| November | 2.9 °C | 11.1 °C | 238 mm |
| December | 1.4 °C | 7.8 °C | 231.39 mm |
| Annual | 5.5 °C | 16.5 °C | 1470.66 mm |
| 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 : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8a : -12.2°C to -9.4°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |