Powell, Wyoming has a Cold Desert Climate climate (Köppen classification: BWk). Average annual temperatures range from 0.2 °C (low) to 15.1 °C (high). Annual precipitation averages 179.3 Millimeters. Powell is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -12.1 °C | 1 °C | 4.83 mm |
| February | -10.1 °C | 3.2 °C | 5.08 mm |
| March | -4.8 °C | 9.9 °C | 6.6 mm |
| April | -0.3 °C | 14.5 °C | 15.24 mm |
| May | 5.1 °C | 19.6 °C | 34.54 mm |
| June | 9.6 °C | 25.3 °C | 32.26 mm |
| July | 13 °C | 30.3 °C | 24.38 mm |
| August | 11.7 °C | 29.6 °C | 9.91 mm |
| September | 6.6 °C | 23.7 °C | 21.59 mm |
| October | 0.2 °C | 15.2 °C | 16.26 mm |
| November | -6.1 °C | 7.1 °C | 5.08 mm |
| December | -11 °C | 1.3 °C | 3.56 mm |
| Annual | 0.2 °C | 15.1 °C | 179.33 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 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 | BWk - Cold Desert Climate |