Oroville, Washington has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 4.3 °C (low) to 16.4 °C (high). Annual precipitation averages 355.1 Millimeters. Oroville is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -3.8 °C | 1.5 °C | 42.42 mm |
| February | -3.1 °C | 5.4 °C | 22.61 mm |
| March | -0.1 °C | 11.7 °C | 30.73 mm |
| April | 3.3 °C | 17.4 °C | 23.62 mm |
| May | 7.7 °C | 22.8 °C | 29.21 mm |
| June | 11.4 °C | 26.2 °C | 49.78 mm |
| July | 14.3 °C | 31.1 °C | 24.13 mm |
| August | 13.6 °C | 30.8 °C | 14.73 mm |
| September | 8.8 °C | 24.9 °C | 12.95 mm |
| October | 3.9 °C | 16.2 °C | 25.4 mm |
| November | -0.3 °C | 7.3 °C | 33.53 mm |
| December | -3.6 °C | 1.7 °C | 45.97 mm |
| Annual | 4.3 °C | 16.4 °C | 355.08 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |