Gregory, South Dakota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 36.1 °F (low) to 59.9 °F (high). Annual precipitation averages 26.2 Inches. Gregory is located in USDA Plant Hardiness Zone 5a. 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 | 11.6 °F | 32.8 °F | 0.51 in. |
| February | 14.8 °F | 37.1 °F | 0.74 in. |
| March | 23.6 °F | 47.7 °F | 1.21 in. |
| April | 34.0 °F | 58.0 °F | 2.91 in. |
| May | 45.4 °F | 69.3 °F | 4.08 in. |
| June | 56.3 °F | 79.8 °F | 4.39 in. |
| July | 61.9 °F | 87.1 °F | 2.93 in. |
| August | 59.6 °F | 85.0 °F | 3.22 in. |
| September | 50.3 °F | 76.9 °F | 2.51 in. |
| October | 36.5 °F | 62.2 °F | 2.28 in. |
| November | 24.1 °F | 47.1 °F | 0.75 in. |
| December | 14.9 °F | 35.3 °F | 0.67 in. |
| Annual | 36.1 °F | 59.9 °F | 26.2 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 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |