Pierpont, South Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 0.6 °C (low) to 12.2 °C (high). Annual precipitation averages 606 Millimeters. Pierpont 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 | -16.3 °C | -6.1 °C | 15.24 mm |
| February | -14 °C | -3.2 °C | 14.73 mm |
| March | -7.2 °C | 3.8 °C | 26.92 mm |
| April | 0 °C | 12.6 °C | 55.63 mm |
| May | 7.3 °C | 19.8 °C | 80.26 mm |
| June | 13.3 °C | 25.2 °C | 104.14 mm |
| July | 15.8 °C | 27.8 °C | 94.74 mm |
| August | 14.6 °C | 27.2 °C | 60.71 mm |
| September | 9.7 °C | 22.7 °C | 60.45 mm |
| October | 1.9 °C | 14.3 °C | 55.12 mm |
| November | -5.7 °C | 4.7 °C | 20.57 mm |
| December | -12.5 °C | -2.9 °C | 17.53 mm |
| Annual | 0.6 °C | 12.2 °C | 606.04 mm |
| 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 : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |