Kelly, Wyoming has a Subarctic With Cool Summers And Year Around Rainfall climate (Köppen classification: Dfc). Average annual temperatures range from -5 °C (low) to 10.8 °C (high). Annual precipitation averages 502.7 Millimeters. 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 | -15.4 °C | -3.1 °C | 58.67 mm |
| February | -14.3 °C | -0.4 °C | 41.91 mm |
| March | -9.9 °C | 4.5 °C | 38.61 mm |
| April | -5.1 °C | 8.9 °C | 43.94 mm |
| May | -0.7 °C | 15 °C | 49.02 mm |
| June | 2.8 °C | 20.4 °C | 39.37 mm |
| July | 5.5 °C | 26.3 °C | 24.38 mm |
| August | 4.4 °C | 25.7 °C | 26.16 mm |
| September | 0.7 °C | 20.2 °C | 35.81 mm |
| October | -3.9 °C | 11.8 °C | 40.39 mm |
| November | -9.7 °C | 2.9 °C | 45.72 mm |
| December | -14.9 °C | -3.1 °C | 58.67 mm |
| Annual | -5 °C | 10.8 °C | 502.65 mm |
| 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 : -34.4°C to -31.7°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfc - Subarctic With Cool Summers And Year Around Rainfall |