Jamestown, Ohio has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.9 °C (low) to 16.6 °C (high). Annual precipitation averages 1069.6 Millimeters. Jamestown is located in USDA Plant Hardiness Zone 6b. 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 | -6.3 °C | 2.3 °C | 78.74 mm |
| February | -5.1 °C | 4.3 °C | 62.74 mm |
| March | -0.6 °C | 9.9 °C | 89.92 mm |
| April | 5.2 °C | 17.1 °C | 107.7 mm |
| May | 11.2 °C | 22.6 °C | 118.36 mm |
| June | 16.1 °C | 27.1 °C | 116.59 mm |
| July | 17.5 °C | 28.6 °C | 109.22 mm |
| August | 16.3 °C | 28.1 °C | 81.03 mm |
| September | 12.4 °C | 25.2 °C | 74.93 mm |
| October | 6.5 °C | 18.5 °C | 74.93 mm |
| November | 0.9 °C | 11.1 °C | 76.2 mm |
| December | -3.3 °C | 4.7 °C | 79.25 mm |
| Annual | 5.9 °C | 16.6 °C | 1069.61 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |