Fort Washakie, Wyoming has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from -1.5 °C (low) to 14.9 °C (high). Annual precipitation averages 342.6 Millimeters. Fort Washakie is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -13.5 °C | 1.2 °C | 12.45 mm |
| February | -11.8 °C | 3.3 °C | 15.24 mm |
| March | -6.1 °C | 9.3 °C | 27.69 mm |
| April | -1.9 °C | 13.9 °C | 55.37 mm |
| May | 3 °C | 18.8 °C | 72.64 mm |
| June | 7.2 °C | 25.1 °C | 33.27 mm |
| July | 11 °C | 30.3 °C | 19.56 mm |
| August | 9.9 °C | 29.3 °C | 17.78 mm |
| September | 5.3 °C | 23.6 °C | 29.97 mm |
| October | -0.9 °C | 15.6 °C | 33.27 mm |
| November | -7.6 °C | 7.1 °C | 17.53 mm |
| December | -12.7 °C | 1.2 °C | 7.87 mm |
| Annual | -1.5 °C | 14.9 °C | 342.64 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |