Salem, Connecticut has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 40.6 °F (low) to 60.5 °F (high). Annual precipitation averages 50.7 Inches. Salem is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 19.6 °F | 36.7 °F | 3.89 in. |
| February | 20.8 °F | 39.3 °F | 3.38 in. |
| March | 27.9 °F | 46.9 °F | 4.7 in. |
| April | 37.6 °F | 59.1 °F | 4.58 in. |
| May | 47.1 °F | 69.1 °F | 3.71 in. |
| June | 56.6 °F | 77.6 °F | 4.24 in. |
| July | 62.4 °F | 82.8 °F | 3.73 in. |
| August | 60.9 °F | 81.5 °F | 4.24 in. |
| September | 53.3 °F | 74.6 °F | 4.47 in. |
| October | 42.5 °F | 63.3 °F | 4.94 in. |
| November | 33.1 °F | 52.3 °F | 4.11 in. |
| December | 25.6 °F | 42.4 °F | 4.75 in. |
| Annual | 40.6 °F | 60.5 °F | 50.74 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |