Salem, South Dakota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 1.4 °C (low) to 13.3 °C (high). Annual precipitation averages 679 Millimeters. Salem is located in USDA Plant Hardiness Zone 5a. 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 | -14.3 °C | -3.9 °C | 13.72 mm |
| February | -11.9 °C | -1.1 °C | 19.05 mm |
| March | -5.8 °C | 5.7 °C | 31.5 mm |
| April | 0.8 °C | 13.5 °C | 74.42 mm |
| May | 7.8 °C | 20.3 °C | 95.76 mm |
| June | 14.1 °C | 25.9 °C | 104.14 mm |
| July | 16.4 °C | 28.7 °C | 82.04 mm |
| August | 14.9 °C | 27.2 °C | 80.77 mm |
| September | 9.9 °C | 23.3 °C | 77.22 mm |
| October | 2.2 °C | 15.5 °C | 58.17 mm |
| November | -5.4 °C | 6.2 °C | 24.64 mm |
| December | -11.4 °C | -1.4 °C | 17.53 mm |
| Annual | 1.4 °C | 13.3 °C | 678.96 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 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |