Grover, Wyoming has a Subarctic With Cool Summers And Year Around Rainfall climate (Köppen classification: Dfc). Average annual temperatures range from 25.1 °F (low) to 53.4 °F (high). Annual precipitation averages 20.9 Inches. Grover is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around Jun. 1 - Jun. 10 through the first frost around Aug. 11 - Aug. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 6.2 °F | 28.2 °F | 1.91 in. |
| February | 8.1 °F | 32.0 °F | 1.71 in. |
| March | 16.6 °F | 41.3 °F | 1.74 in. |
| April | 25.3 °F | 50.0 °F | 2.01 in. |
| May | 33.3 °F | 61.0 °F | 2.68 in. |
| June | 38.4 °F | 70.6 °F | 1.83 in. |
| July | 43.8 °F | 80.8 °F | 0.99 in. |
| August | 42.4 °F | 80.2 °F | 1.17 in. |
| September | 34.7 °F | 70.7 °F | 1.5 in. |
| October | 26.8 °F | 56.1 °F | 1.78 in. |
| November | 17.5 °F | 40.7 °F | 1.68 in. |
| December | 7.6 °F | 28.7 °F | 1.93 in. |
| Annual | 25.1 °F | 53.4 °F | 20.93 in. |
| Average First Frost Date | Aug. 11 - Aug. 20 |
| Average Last Frost Date | Jun. 1 - Jun. 10 |
| Average Days With Frost | Over 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 | Extreme Drought |
| Köppen Climate Classification | Dfc - Subarctic With Cool Summers And Year Around Rainfall |