Wasco, Oregon has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 4.4 °C (low) to 17.1 °C (high). Annual precipitation averages 307.4 Millimeters. Wasco is located in USDA Plant Hardiness Zone 7a. 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 | -2.1 °C | 4.8 °C | 47.5 mm |
| February | -1.3 °C | 7.7 °C | 30.99 mm |
| March | 0.7 °C | 12.2 °C | 25.4 mm |
| April | 3.1 °C | 16.1 °C | 24.13 mm |
| May | 6.5 °C | 21.1 °C | 22.86 mm |
| June | 9.7 °C | 24.8 °C | 17.02 mm |
| July | 12.4 °C | 30.3 °C | 5.08 mm |
| August | 12.3 °C | 30.2 °C | 5.84 mm |
| September | 9.1 °C | 25.8 °C | 9.91 mm |
| October | 3.9 °C | 17.8 °C | 27.69 mm |
| November | 0.4 °C | 9.4 °C | 41.4 mm |
| December | -2.2 °C | 4.4 °C | 49.53 mm |
| Annual | 4.4 °C | 17.1 °C | 307.35 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| 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 | Normal |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |