Hannibal, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 38.9 °F (low) to 56.5 °F (high). Annual precipitation averages 44.9 Inches. Hannibal 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. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 16.0 °F | 31.4 °F | 3.93 in. |
| February | 17.0 °F | 33.1 °F | 3.08 in. |
| March | 24.1 °F | 41.1 °F | 3.24 in. |
| April | 35.1 °F | 54.4 °F | 3.59 in. |
| May | 46.4 °F | 67.4 °F | 3.49 in. |
| June | 55.6 °F | 75.5 °F | 3.61 in. |
| July | 60.8 °F | 80.0 °F | 3.64 in. |
| August | 59.6 °F | 79.1 °F | 3.71 in. |
| September | 52.8 °F | 72.4 °F | 3.75 in. |
| October | 42.5 °F | 59.2 °F | 4.68 in. |
| November | 33.0 °F | 47.9 °F | 4.06 in. |
| December | 23.6 °F | 36.8 °F | 4.15 in. |
| Annual | 38.9 °F | 56.5 °F | 44.93 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 6a : -10°F to -5°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 |