Green River, Wyoming has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 29 °F (low) to 59.3 °F (high). Annual precipitation averages 10 Inches. Green River is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around Jun. 1 - Jun. 10 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 8.0 °F | 33.7 °F | 0.6 in. |
| February | 11.6 °F | 37.4 °F | 0.54 in. |
| March | 21.5 °F | 48.0 °F | 0.79 in. |
| April | 28.0 °F | 57.1 °F | 1.18 in. |
| May | 36.6 °F | 66.9 °F | 1.56 in. |
| June | 44.4 °F | 78.7 °F | 0.97 in. |
| July | 50.9 °F | 87.3 °F | 0.51 in. |
| August | 49.1 °F | 85.5 °F | 0.63 in. |
| September | 39.8 °F | 75.9 °F | 1.0 in. |
| October | 29.3 °F | 61.4 °F | 1.05 in. |
| November | 19.2 °F | 45.7 °F | 0.67 in. |
| December | 9.9 °F | 34.4 °F | 0.52 in. |
| Annual | 29 °F | 59.3 °F | 10.02 in. |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | Jun. 1 - Jun. 10 |
| 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 | Severe Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |