McLaughlin, South Dakota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 31.9 °F (low) to 55.5 °F (high). Annual precipitation averages 18.4 Inches. 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 | 4.6 °F | 24.2 °F | 0.44 in. |
| February | 8.7 °F | 29.1 °F | 0.51 in. |
| March | 19.0 °F | 41.2 °F | 0.82 in. |
| April | 30.5 °F | 55.7 °F | 1.43 in. |
| May | 42.4 °F | 67.5 °F | 2.88 in. |
| June | 53.0 °F | 77.7 °F | 3.11 in. |
| July | 58.5 °F | 84.9 °F | 2.85 in. |
| August | 56.3 °F | 84.1 °F | 2.24 in. |
| September | 46.7 °F | 73.9 °F | 1.45 in. |
| October | 33.5 °F | 57.6 °F | 1.65 in. |
| November | 20.3 °F | 41.4 °F | 0.46 in. |
| December | 9.7 °F | 28.7 °F | 0.53 in. |
| Annual | 31.9 °F | 55.5 °F | 18.37 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 4a : -30°F to -25°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |