New Effington, South Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 32.7 °F (low) to 53 °F (high). Annual precipitation averages 25.7 Inches. New Effington 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 | 1.9 °F | 20.0 °F | 0.78 in. |
| February | 5.6 °F | 24.4 °F | 0.71 in. |
| March | 18.3 °F | 37.1 °F | 1.13 in. |
| April | 32.0 °F | 53.5 °F | 2.21 in. |
| May | 45.3 °F | 67.6 °F | 3.09 in. |
| June | 56.5 °F | 77.2 °F | 4.25 in. |
| July | 60.5 °F | 81.6 °F | 3.84 in. |
| August | 57.6 °F | 79.9 °F | 2.75 in. |
| September | 48.4 °F | 72.1 °F | 2.7 in. |
| October | 35.3 °F | 56.8 °F | 2.43 in. |
| November | 21.8 °F | 39.8 °F | 0.96 in. |
| December | 9.1 °F | 25.9 °F | 0.83 in. |
| Annual | 32.7 °F | 53 °F | 25.68 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 | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |