Casper Mountain, Wyoming has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -1.7 °C (low) to 9.4 °C (high). Annual precipitation averages 666.8 Millimeters. Casper Mountain is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around Jun. 1 - Jun. 10 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -11.1 °C | -3.1 °C | 44.2 mm |
| February | -11 °C | -2.2 °C | 50.29 mm |
| March | -7.3 °C | 3.1 °C | 65.79 mm |
| April | -4.4 °C | 7.3 °C | 88.9 mm |
| May | 0.6 °C | 12.7 °C | 105.41 mm |
| June | 5.8 °C | 19.5 °C | 54.36 mm |
| July | 10.4 °C | 24.8 °C | 25.65 mm |
| August | 9.9 °C | 24 °C | 23.88 mm |
| September | 5.2 °C | 18.2 °C | 44.7 mm |
| October | -1.3 °C | 9.9 °C | 68.07 mm |
| November | -6.7 °C | 2 °C | 45.47 mm |
| December | -10.9 °C | -3.3 °C | 50.04 mm |
| Annual | -1.7 °C | 9.4 °C | 666.76 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | Jun. 1 - Jun. 10 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |