Guilford, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 1.3 °C (low) to 13.4 °C (high). Annual precipitation averages 1213.1 Millimeters. Guilford is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -11.1 °C | -0.7 °C | 84.07 mm |
| February | -10.4 °C | 0.6 °C | 72.64 mm |
| March | -6.9 °C | 5.1 °C | 93.73 mm |
| April | -0.9 °C | 12.8 °C | 104.9 mm |
| May | 5.3 °C | 19.9 °C | 101.35 mm |
| June | 10.6 °C | 23.8 °C | 122.94 mm |
| July | 14.4 °C | 26.1 °C | 118.62 mm |
| August | 12.2 °C | 25.9 °C | 116.33 mm |
| September | 8.6 °C | 22.4 °C | 105.92 mm |
| October | 2.9 °C | 15 °C | 109.73 mm |
| November | -2.3 °C | 8 °C | 92.46 mm |
| December | -6.8 °C | 1.9 °C | 90.42 mm |
| Annual | 1.3 °C | 13.4 °C | 1213.11 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |