Grover, Colorado has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 32.6 °F (low) to 62.4 °F (high). Annual precipitation averages 14.5 Inches. Grover is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 14.1 °F | 40.7 °F | 0.26 in. |
| February | 15.3 °F | 42.7 °F | 0.32 in. |
| March | 22.7 °F | 52.3 °F | 0.73 in. |
| April | 29.8 °F | 59.3 °F | 1.52 in. |
| May | 39.6 °F | 68.5 °F | 2.52 in. |
| June | 49.2 °F | 80.5 °F | 2.19 in. |
| July | 55.4 °F | 87.9 °F | 2.0 in. |
| August | 53.1 °F | 85.7 °F | 1.81 in. |
| September | 44.4 °F | 77.4 °F | 1.36 in. |
| October | 32.1 °F | 63.0 °F | 1.04 in. |
| November | 21.6 °F | 49.8 °F | 0.45 in. |
| December | 13.8 °F | 40.8 °F | 0.32 in. |
| Annual | 32.6 °F | 62.4 °F | 14.52 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |