Van Tassell, Wyoming has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 31.2 °F (low) to 59.6 °F (high). Annual precipitation averages 15.9 Inches. Van Tassell is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 12.1 °F | 37.7 °F | 0.31 in. |
| February | 14.1 °F | 39.2 °F | 0.49 in. |
| March | 21.7 °F | 49.5 °F | 0.94 in. |
| April | 28.7 °F | 55.5 °F | 1.93 in. |
| May | 38.5 °F | 65.1 °F | 3.03 in. |
| June | 48.2 °F | 77.0 °F | 2.45 in. |
| July | 54.6 °F | 85.9 °F | 1.89 in. |
| August | 52.4 °F | 84.8 °F | 1.33 in. |
| September | 42.4 °F | 75.4 °F | 1.31 in. |
| October | 30.0 °F | 59.9 °F | 1.34 in. |
| November | 19.5 °F | 47.8 °F | 0.52 in. |
| December | 12.4 °F | 37.9 °F | 0.38 in. |
| Annual | 31.2 °F | 59.6 °F | 15.92 in. |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |