McLaughlin, South Dakota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Annual precipitation averages 466.6 Millimeters. McLaughlin 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 | -15.2 °C | -4.3 °C | 11.18 mm |
| February | -12.9 °C | -1.6 °C | 12.95 mm |
| March | -7.2 °C | 5.1 °C | 20.83 mm |
| April | -0.8 °C | 13.2 °C | 36.32 mm |
| May | 5.8 °C | 19.7 °C | 73.15 mm |
| June | 11.7 °C | 25.4 °C | 78.99 mm |
| July | 14.7 °C | 29.4 °C | 72.39 mm |
| August | 13.5 °C | 28.9 °C | 56.9 mm |
| September | 8.2 °C | 23.3 °C | 36.83 mm |
| October | 0.8 °C | 14.2 °C | 41.91 mm |
| November | -6.5 °C | 5.2 °C | 11.68 mm |
| December | -12.4 °C | -1.8 °C | 13.46 mm |
| Annual | -0 °C | 13.1 °C | 466.59 mm |
| 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 : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |