Farnham, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 41.7 °F (low) to 56.4 °F (high). Annual precipitation averages 41.4 Inches. Farnham 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. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 20.1 °F | 32.9 °F | 3.27 in. |
| February | 19.9 °F | 33.9 °F | 2.27 in. |
| March | 26.1 °F | 41.1 °F | 2.71 in. |
| April | 36.4 °F | 53.5 °F | 3.21 in. |
| May | 48.0 °F | 65.1 °F | 3.47 in. |
| June | 58.4 °F | 74.1 °F | 3.49 in. |
| July | 63.6 °F | 78.4 °F | 3.84 in. |
| August | 62.7 °F | 77.8 °F | 3.46 in. |
| September | 56.2 °F | 72.2 °F | 3.94 in. |
| October | 45.6 °F | 60.3 °F | 4.24 in. |
| November | 35.9 °F | 48.6 °F | 3.72 in. |
| December | 27.1 °F | 38.5 °F | 3.73 in. |
| Annual | 41.7 °F | 56.4 °F | 41.35 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| 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 | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |