Edgemont, South Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 33.2 °F (low) to 62.4 °F (high). Annual precipitation averages 16.4 Inches. Edgemont is located in USDA Plant Hardiness Zone 4b. 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 | 10.7 °F | 36.9 °F | 0.38 in. |
| February | 14.3 °F | 40.8 °F | 0.47 in. |
| March | 23.0 °F | 51.7 °F | 0.89 in. |
| April | 31.2 °F | 60.3 °F | 1.84 in. |
| May | 42.1 °F | 69.5 °F | 2.74 in. |
| June | 51.9 °F | 80.9 °F | 2.72 in. |
| July | 58.6 °F | 89.9 °F | 2.29 in. |
| August | 56.0 °F | 88.9 °F | 1.46 in. |
| September | 45.7 °F | 79.3 °F | 1.28 in. |
| October | 32.8 °F | 63.3 °F | 1.28 in. |
| November | 20.6 °F | 48.9 °F | 0.57 in. |
| December | 11.9 °F | 38.0 °F | 0.46 in. |
| Annual | 33.2 °F | 62.4 °F | 16.38 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 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 | Dfb - Humid Continental Mild Summer, Wet All Year |