Greybull, Wyoming has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 31.2 °F (low) to 60.3 °F (high). Annual precipitation averages 6.8 Inches. Greybull is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 4.7 °F | 29.4 °F | 0.24 in. |
| February | 10.5 °F | 36.3 °F | 0.27 in. |
| March | 22.4 °F | 50.8 °F | 0.27 in. |
| April | 31.8 °F | 60.6 °F | 0.66 in. |
| May | 42.3 °F | 70.3 °F | 1.28 in. |
| June | 50.8 °F | 81.2 °F | 1.15 in. |
| July | 56.8 °F | 90.8 °F | 0.46 in. |
| August | 53.5 °F | 88.8 °F | 0.3 in. |
| September | 43.5 °F | 77.3 °F | 0.85 in. |
| October | 31.7 °F | 61.5 °F | 0.7 in. |
| November | 18.7 °F | 44.7 °F | 0.37 in. |
| December | 7.4 °F | 31.7 °F | 0.24 in. |
| Annual | 31.2 °F | 60.3 °F | 6.79 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4b : -25°F to -20°F |
| Plant Hardiness Zone - 2012 | Zone 4a : -30°F to -25°F |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |