Shell, Wyoming has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 31 °F (low) to 60 °F (high). Annual precipitation averages 9.8 Inches. Shell is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 7.5 °F | 33.1 °F | 0.5 in. |
| February | 11.8 °F | 37.7 °F | 0.67 in. |
| March | 22.5 °F | 50.3 °F | 0.54 in. |
| April | 30.8 °F | 58.9 °F | 1.05 in. |
| May | 40.4 °F | 68.5 °F | 1.76 in. |
| June | 48.9 °F | 79.3 °F | 1.42 in. |
| July | 54.8 °F | 88.8 °F | 0.56 in. |
| August | 52.0 °F | 87.2 °F | 0.4 in. |
| September | 42.8 °F | 75.8 °F | 0.87 in. |
| October | 31.3 °F | 60.5 °F | 0.99 in. |
| November | 19.4 °F | 45.6 °F | 0.61 in. |
| December | 9.4 °F | 34.5 °F | 0.42 in. |
| Annual | 31 °F | 60 °F | 9.79 in. |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 4b : -25°F to -20°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 |