Marcellus, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 38.7 °F (low) to 56.8 °F (high). Annual precipitation averages 44.2 Inches. Marcellus is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 15.7 °F | 31.5 °F | 3.05 in. |
| February | 16.3 °F | 33.3 °F | 2.6 in. |
| March | 23.9 °F | 41.1 °F | 3.33 in. |
| April | 35.5 °F | 55.2 °F | 3.72 in. |
| May | 46.9 °F | 68.2 °F | 3.62 in. |
| June | 56.0 °F | 76.2 °F | 4.16 in. |
| July | 60.8 °F | 80.7 °F | 4.19 in. |
| August | 59.4 °F | 79.3 °F | 3.91 in. |
| September | 52.4 °F | 72.6 °F | 4.12 in. |
| October | 42.0 °F | 59.7 °F | 4.31 in. |
| November | 32.4 °F | 47.5 °F | 3.71 in. |
| December | 23.0 °F | 36.6 °F | 3.46 in. |
| Annual | 38.7 °F | 56.8 °F | 44.18 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 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 |