Milbank, South Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 33.1 °F (low) to 54.1 °F (high). Annual precipitation averages 24.9 Inches. Milbank is located in USDA Plant Hardiness Zone 4b. 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 | 3.2 °F | 21.9 °F | 0.61 in. |
| February | 6.5 °F | 26.2 °F | 0.61 in. |
| March | 19.2 °F | 38.4 °F | 1.15 in. |
| April | 32.1 °F | 54.4 °F | 2.53 in. |
| May | 45.4 °F | 67.8 °F | 2.89 in. |
| June | 56.6 °F | 77.9 °F | 3.93 in. |
| July | 60.4 °F | 82.2 °F | 3.9 in. |
| August | 57.7 °F | 80.3 °F | 3.02 in. |
| September | 48.5 °F | 72.7 °F | 2.3 in. |
| October | 35.3 °F | 57.8 °F | 2.29 in. |
| November | 22.4 °F | 41.6 °F | 0.91 in. |
| December | 10.0 °F | 27.4 °F | 0.74 in. |
| Annual | 33.1 °F | 54.1 °F | 24.88 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 4b : -25°F to -20°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |