Mission, Oregon has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 4.5 °C (low) to 18.1 °C (high). Annual precipitation averages 389.4 Millimeters. Mission 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. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -2.2 °C | 5.9 °C | 43.43 mm |
| February | -1.4 °C | 8.7 °C | 35.05 mm |
| March | 0.9 °C | 13.4 °C | 41.4 mm |
| April | 3.3 °C | 17.1 °C | 39.37 mm |
| May | 7.1 °C | 22.1 °C | 44.45 mm |
| June | 10.3 °C | 26.1 °C | 30.73 mm |
| July | 13.2 °C | 32.1 °C | 7.87 mm |
| August | 12.6 °C | 31.5 °C | 10.67 mm |
| September | 8.4 °C | 26.3 °C | 13.46 mm |
| October | 3.6 °C | 18.5 °C | 29.21 mm |
| November | 0.1 °C | 10.3 °C | 46.48 mm |
| December | -2.3 °C | 5.6 °C | 47.24 mm |
| Annual | 4.5 °C | 18.1 °C | 389.36 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| 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 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |