Langford, South Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 0.3 °C (low) to 12.1 °C (high). Annual precipitation averages 601.7 Millimeters. Langford is located in USDA Plant Hardiness Zone 4a. 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 | -16.7 °C | -6.3 °C | 15.24 mm |
| February | -14.2 °C | -3.4 °C | 15.49 mm |
| March | -7.4 °C | 3.6 °C | 25.15 mm |
| April | -0.1 °C | 12.6 °C | 51.31 mm |
| May | 7.2 °C | 20 °C | 80.77 mm |
| June | 13.3 °C | 25.3 °C | 103.12 mm |
| July | 15.8 °C | 27.9 °C | 96.01 mm |
| August | 14.3 °C | 27.3 °C | 60.96 mm |
| September | 9.2 °C | 22.7 °C | 61.47 mm |
| October | 1.6 °C | 14.3 °C | 55.37 mm |
| November | -6.1 °C | 4.5 °C | 19.56 mm |
| December | -12.8 °C | -3.1 °C | 17.27 mm |
| Annual | 0.3 °C | 12.1 °C | 601.72 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 4a : -34.4°C to -31.7°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 |