Kelly, Wyoming has a Subarctic With Cool Summers And Year Around Rainfall climate (Köppen classification: Dfc). Average annual temperatures range from 22.9 °F (low) to 51.4 °F (high). Annual precipitation averages 19.8 Inches. Kelly is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around Jun. 21 - Jun. 30 through the first frost around Aug. 1 - Aug. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 4.3 °F | 26.5 °F | 2.31 in. |
| February | 6.3 °F | 31.2 °F | 1.65 in. |
| March | 14.2 °F | 40.1 °F | 1.52 in. |
| April | 22.8 °F | 48.1 °F | 1.73 in. |
| May | 30.8 °F | 59.0 °F | 1.93 in. |
| June | 37.0 °F | 68.8 °F | 1.55 in. |
| July | 41.9 °F | 79.3 °F | 0.96 in. |
| August | 40.0 °F | 78.3 °F | 1.03 in. |
| September | 33.2 °F | 68.4 °F | 1.41 in. |
| October | 25.0 °F | 53.2 °F | 1.59 in. |
| November | 14.5 °F | 37.3 °F | 1.8 in. |
| December | 5.2 °F | 26.5 °F | 2.31 in. |
| Annual | 22.9 °F | 51.4 °F | 19.79 in. |
| Average First Frost Date | Aug. 1 - Aug. 10 |
| Average Last Frost Date | Jun. 21 - Jun. 30 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 4a : -30°F to -25°F |
| Plant Hardiness Zone - 2012 | Zone 4a : -30°F to -25°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfc - Subarctic With Cool Summers And Year Around Rainfall |