Carthage, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 1.8 °C (low) to 12.3 °C (high). Annual precipitation averages 1120.9 Millimeters. Carthage is located in USDA Plant Hardiness Zone 4b. 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 | -12.9 °C | -2.5 °C | 95 mm |
| February | -12.3 °C | -1.4 °C | 69.34 mm |
| March | -6.9 °C | 3.4 °C | 71.63 mm |
| April | 0.4 °C | 11.4 °C | 86.61 mm |
| May | 7.2 °C | 18.8 °C | 92.2 mm |
| June | 12.4 °C | 23.4 °C | 96.52 mm |
| July | 15.2 °C | 25.9 °C | 91.44 mm |
| August | 14.3 °C | 25.4 °C | 96.01 mm |
| September | 9.8 °C | 21.5 °C | 97.54 mm |
| October | 3.8 °C | 14.3 °C | 124.97 mm |
| November | -1.9 °C | 7.2 °C | 101.6 mm |
| December | -7.9 °C | 0.7 °C | 98.04 mm |
| Annual | 1.8 °C | 12.3 °C | 1120.9 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 4b : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |