Great Valley, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 34.9 °F (low) to 56.3 °F (high). Annual precipitation averages 46 Inches. Great Valley 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 | 13.6 °F | 31.0 °F | 3.44 in. |
| February | 13.9 °F | 33.3 °F | 2.48 in. |
| March | 20.8 °F | 42.0 °F | 3.08 in. |
| April | 31.6 °F | 55.4 °F | 3.78 in. |
| May | 42.7 °F | 67.9 °F | 3.88 in. |
| June | 51.4 °F | 75.6 °F | 4.61 in. |
| July | 55.7 °F | 79.4 °F | 4.73 in. |
| August | 54.3 °F | 77.9 °F | 4.31 in. |
| September | 47.8 °F | 71.5 °F | 4.15 in. |
| October | 37.2 °F | 59.2 °F | 4.23 in. |
| November | 28.7 °F | 46.6 °F | 3.65 in. |
| December | 20.8 °F | 36.0 °F | 3.7 in. |
| Annual | 34.9 °F | 56.3 °F | 46.04 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 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |