Salem, Missouri has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 7 °C (low) to 19.5 °C (high). Annual precipitation averages 1185.7 Millimeters. Salem is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.1 °C | 5.8 °C | 65.28 mm |
| February | -3.3 °C | 8.9 °C | 70.1 mm |
| March | 1.1 °C | 14.2 °C | 101.85 mm |
| April | 6.8 °C | 20.3 °C | 130.3 mm |
| May | 11.9 °C | 24.6 °C | 146.05 mm |
| June | 16.9 °C | 28.9 °C | 112.52 mm |
| July | 18.9 °C | 31.2 °C | 98.04 mm |
| August | 17.9 °C | 31 °C | 101.09 mm |
| September | 13.4 °C | 26.9 °C | 105.41 mm |
| October | 7.1 °C | 21.1 °C | 81.79 mm |
| November | 1.7 °C | 13.6 °C | 103.63 mm |
| December | -3.2 °C | 7.7 °C | 69.6 mm |
| Annual | 7 °C | 19.5 °C | 1185.66 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |