Jamestown, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.4 °C (low) to 13.6 °C (high). Annual precipitation averages 1164.9 Millimeters. Jamestown 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 | -9.3 °C | -0.4 °C | 92.2 mm |
| February | -9.2 °C | 0.9 °C | 65.53 mm |
| March | -5.3 °C | 5.8 °C | 79.76 mm |
| April | 0.6 °C | 13.1 °C | 99.57 mm |
| May | 6.7 °C | 19.7 °C | 100.08 mm |
| June | 11.7 °C | 24.1 °C | 111.76 mm |
| July | 13.8 °C | 26.3 °C | 113.28 mm |
| August | 13.2 °C | 25.6 °C | 101.6 mm |
| September | 9.6 °C | 22.1 °C | 99.06 mm |
| October | 3.8 °C | 15.1 °C | 107.7 mm |
| November | -1.1 °C | 8.2 °C | 93.47 mm |
| December | -5.3 °C | 2.3 °C | 100.84 mm |
| Annual | 2.4 °C | 13.6 °C | 1164.85 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |