New Salem, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.9 °C (low) to 17 °C (high). Annual precipitation averages 998.2 Millimeters. New Salem is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.8 °C | 1.6 °C | 50.8 mm |
| February | -5.8 °C | 4.4 °C | 49.53 mm |
| March | -0.6 °C | 10.7 °C | 69.09 mm |
| April | 5.4 °C | 17.6 °C | 104.39 mm |
| May | 11.8 °C | 22.9 °C | 118.11 mm |
| June | 16.9 °C | 27.7 °C | 121.16 mm |
| July | 18.6 °C | 29.8 °C | 106.68 mm |
| August | 17.4 °C | 29.2 °C | 86.11 mm |
| September | 12.5 °C | 25.8 °C | 91.69 mm |
| October | 6.2 °C | 18.9 °C | 74.68 mm |
| November | 0.6 °C | 11.1 °C | 72.14 mm |
| December | -4.8 °C | 4.2 °C | 53.85 mm |
| Annual | 5.9 °C | 17 °C | 998.23 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |