Othello, Washington has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 3.9 °C (low) to 16.8 °C (high). Annual precipitation averages 209.3 Millimeters. Othello 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 | -3.7 °C | 3 °C | 29.72 mm |
| February | -2.4 °C | 7 °C | 18.8 mm |
| March | 0.1 °C | 12.6 °C | 21.34 mm |
| April | 2.7 °C | 17.1 °C | 17.27 mm |
| May | 6.8 °C | 22.1 °C | 17.53 mm |
| June | 10 °C | 25.6 °C | 16.51 mm |
| July | 13.2 °C | 30.7 °C | 5.84 mm |
| August | 12.8 °C | 30.2 °C | 4.57 mm |
| September | 8.7 °C | 25.3 °C | 7.37 mm |
| October | 3.6 °C | 17.2 °C | 19.3 mm |
| November | -0.8 °C | 8.5 °C | 24.13 mm |
| December | -3.8 °C | 2.7 °C | 26.92 mm |
| Annual | 3.9 °C | 16.8 °C | 209.3 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 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |