Harrold, South Dakota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 33.5 °F (low) to 57.6 °F (high). Annual precipitation averages 20.5 Inches. Harrold 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 Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 6.1 °F | 26.8 °F | 0.44 in. |
| February | 10.1 °F | 31.3 °F | 0.61 in. |
| March | 20.5 °F | 43.9 °F | 0.88 in. |
| April | 31.5 °F | 57.7 °F | 2.08 in. |
| May | 43.7 °F | 69.0 °F | 3.17 in. |
| June | 54.7 °F | 78.9 °F | 3.64 in. |
| July | 60.1 °F | 86.2 °F | 2.76 in. |
| August | 58.1 °F | 84.8 °F | 2.3 in. |
| September | 48.8 °F | 76.7 °F | 1.86 in. |
| October | 35.0 °F | 60.4 °F | 1.72 in. |
| November | 21.8 °F | 44.1 °F | 0.58 in. |
| December | 11.1 °F | 30.8 °F | 0.5 in. |
| Annual | 33.5 °F | 57.6 °F | 20.54 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| 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 | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |