Dexter, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 37.1 °F (low) to 55.1 °F (high). Annual precipitation averages 41.2 Inches. Dexter is located in USDA Plant Hardiness Zone 5a. 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 | 11.2 °F | 29.0 °F | 3.61 in. |
| February | 11.7 °F | 30.6 °F | 2.73 in. |
| March | 21.6 °F | 39.0 °F | 2.83 in. |
| April | 34.2 °F | 53.2 °F | 3.41 in. |
| May | 45.9 °F | 65.9 °F | 3.06 in. |
| June | 55.5 °F | 74.6 °F | 3.26 in. |
| July | 61.2 °F | 79.3 °F | 2.98 in. |
| August | 59.5 °F | 78.2 °F | 3.24 in. |
| September | 51.8 °F | 71.4 °F | 3.54 in. |
| October | 41.4 °F | 58.5 °F | 4.76 in. |
| November | 31.0 °F | 46.6 °F | 3.97 in. |
| December | 20.3 °F | 35.2 °F | 3.79 in. |
| Annual | 37.1 °F | 55.1 °F | 41.18 in. |
| 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 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |