Powder River, Wyoming has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 31.5 °F (low) to 58.6 °F (high). Annual precipitation averages 11.3 Inches. Powder River 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. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 13.9 °F | 34.5 °F | 0.39 in. |
| February | 14.3 °F | 36.6 °F | 0.4 in. |
| March | 22.5 °F | 47.0 °F | 1.03 in. |
| April | 29.0 °F | 54.9 °F | 1.26 in. |
| May | 37.8 °F | 65.1 °F | 2.42 in. |
| June | 46.3 °F | 77.6 °F | 1.34 in. |
| July | 53.7 °F | 87.6 °F | 0.94 in. |
| August | 51.7 °F | 85.8 °F | 0.53 in. |
| September | 42.5 °F | 74.7 °F | 1.01 in. |
| October | 31.7 °F | 59.4 °F | 0.99 in. |
| November | 21.3 °F | 45.3 °F | 0.5 in. |
| December | 13.8 °F | 34.8 °F | 0.51 in. |
| Annual | 31.5 °F | 58.6 °F | 11.32 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |