West Carthage, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 1.7 °C (low) to 12.3 °C (high). Annual precipitation averages 1124.2 Millimeters. West 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 | -2.6 °C | 95.5 mm |
| February | -12.3 °C | -1.5 °C | 69.34 mm |
| March | -6.9 °C | 3.3 °C | 71.88 mm |
| April | 0.3 °C | 11.3 °C | 86.87 mm |
| May | 7.1 °C | 18.8 °C | 92.46 mm |
| June | 12.3 °C | 23.3 °C | 96.52 mm |
| July | 15.2 °C | 25.8 °C | 91.44 mm |
| August | 14.3 °C | 25.3 °C | 96.27 mm |
| September | 9.8 °C | 21.5 °C | 97.79 mm |
| October | 3.7 °C | 14.2 °C | 125.48 mm |
| November | -2 °C | 7.2 °C | 102.11 mm |
| December | -8.1 °C | 0.7 °C | 98.55 mm |
| Annual | 1.7 °C | 12.3 °C | 1124.21 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 |