Monticello, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 36.2 °F (low) to 55.7 °F (high). Annual precipitation averages 49.4 Inches. Monticello is located in USDA Plant Hardiness Zone 6a. 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 | 13.6 °F | 30.6 °F | 3.48 in. |
| February | 14.5 °F | 33.7 °F | 2.64 in. |
| March | 22.7 °F | 42.0 °F | 3.7 in. |
| April | 33.7 °F | 54.8 °F | 3.87 in. |
| May | 44.4 °F | 66.3 °F | 4.19 in. |
| June | 53.6 °F | 74.2 °F | 5.01 in. |
| July | 57.8 °F | 79.1 °F | 4.75 in. |
| August | 56.7 °F | 77.2 °F | 4.48 in. |
| September | 49.5 °F | 70.3 °F | 4.85 in. |
| October | 38.6 °F | 58.2 °F | 4.68 in. |
| November | 28.5 °F | 46.3 °F | 3.52 in. |
| December | 20.4 °F | 35.4 °F | 4.18 in. |
| Annual | 36.2 °F | 55.7 °F | 49.35 in. |
| 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 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |