Kirby, Wyoming has a Cold Desert Climate climate (Köppen classification: BWk). Average annual temperatures range from 30 °F (low) to 60.5 °F (high). Annual precipitation averages 10.3 Inches. Kirby 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 Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 4.9 °F | 32.6 °F | 0.27 in. |
| February | 10.4 °F | 38.1 °F | 0.32 in. |
| March | 21.6 °F | 51.4 °F | 0.77 in. |
| April | 30.3 °F | 59.8 °F | 1.18 in. |
| May | 40.2 °F | 68.9 °F | 2.13 in. |
| June | 48.3 °F | 80.1 °F | 1.31 in. |
| July | 54.7 °F | 89.3 °F | 0.69 in. |
| August | 51.7 °F | 87.5 °F | 0.62 in. |
| September | 42.2 °F | 76.7 °F | 1.09 in. |
| October | 30.5 °F | 61.7 °F | 1.01 in. |
| November | 17.5 °F | 45.8 °F | 0.53 in. |
| December | 7.4 °F | 33.7 °F | 0.36 in. |
| Annual | 30 °F | 60.5 °F | 10.28 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| 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 4b : -25°F to -20°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | BWk - Cold Desert Climate |