New Salem, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 42.6 °F (low) to 62.6 °F (high). Annual precipitation averages 39.3 Inches. 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 | 18.0 °F | 34.8 °F | 2.0 in. |
| February | 21.5 °F | 39.9 °F | 1.95 in. |
| March | 31.0 °F | 51.2 °F | 2.72 in. |
| April | 41.8 °F | 63.6 °F | 4.11 in. |
| May | 53.2 °F | 73.3 °F | 4.65 in. |
| June | 62.5 °F | 81.9 °F | 4.77 in. |
| July | 65.5 °F | 85.6 °F | 4.2 in. |
| August | 63.4 °F | 84.5 °F | 3.39 in. |
| September | 54.5 °F | 78.5 °F | 3.61 in. |
| October | 43.2 °F | 66.0 °F | 2.94 in. |
| November | 33.0 °F | 52.0 °F | 2.84 in. |
| December | 23.3 °F | 39.6 °F | 2.12 in. |
| Annual | 42.6 °F | 62.6 °F | 39.3 in. |
| 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 : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |