Hayti, South Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 32.6 °F (low) to 53.9 °F (high). Annual precipitation averages 23.5 Inches. Hayti 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 | 3.0 °F | 22.0 °F | 0.5 in. |
| February | 6.9 °F | 26.7 °F | 0.54 in. |
| March | 19.2 °F | 38.9 °F | 1.12 in. |
| April | 31.4 °F | 54.1 °F | 2.29 in. |
| May | 44.5 °F | 66.9 °F | 3.04 in. |
| June | 55.4 °F | 76.9 °F | 3.77 in. |
| July | 59.9 °F | 82.1 °F | 3.38 in. |
| August | 57.1 °F | 80.1 °F | 2.79 in. |
| September | 48.2 °F | 72.4 °F | 2.69 in. |
| October | 34.4 °F | 57.6 °F | 2.1 in. |
| November | 21.2 °F | 41.2 °F | 0.71 in. |
| December | 9.4 °F | 27.3 °F | 0.58 in. |
| Annual | 32.6 °F | 53.9 °F | 23.51 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 4a : -30°F to -25°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |