Selah, Washington has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 3.3 °C (low) to 17.4 °C (high). Annual precipitation averages 225.8 Millimeters. Selah is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.4 °C | 3.7 °C | 34.8 mm |
| February | -3.1 °C | 7.9 °C | 22.86 mm |
| March | -0.6 °C | 12.8 °C | 19.56 mm |
| April | 2.3 °C | 17.3 °C | 16 mm |
| May | 6.6 °C | 22.4 °C | 22.61 mm |
| June | 9.8 °C | 26.2 °C | 13.46 mm |
| July | 12.8 °C | 31.3 °C | 6.35 mm |
| August | 12.2 °C | 30.8 °C | 4.83 mm |
| September | 7.8 °C | 25.9 °C | 7.87 mm |
| October | 2.4 °C | 17.9 °C | 18.54 mm |
| November | -2 °C | 9.3 °C | 23.11 mm |
| December | -4.8 °C | 3.2 °C | 35.81 mm |
| Annual | 3.3 °C | 17.4 °C | 225.8 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 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 | Moderate Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |