Jamestown, Kansas has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.6 °C (low) to 18.5 °C (high). Annual precipitation averages 759.2 Millimeters. Jamestown is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -8.1 °C | 3.7 °C | 17.53 mm |
| February | -6.2 °C | 6.3 °C | 22.86 mm |
| March | -1.1 °C | 12.9 °C | 38.1 mm |
| April | 4.5 °C | 18.4 °C | 66.55 mm |
| May | 10.9 °C | 23.7 °C | 112.52 mm |
| June | 17 °C | 29.8 °C | 114.81 mm |
| July | 19.7 °C | 32.5 °C | 114.55 mm |
| August | 18.3 °C | 31.1 °C | 90.68 mm |
| September | 13.3 °C | 27.1 °C | 70.36 mm |
| October | 6 °C | 19.9 °C | 50.8 mm |
| November | -1.1 °C | 11.9 °C | 33.78 mm |
| December | -6.2 °C | 5.2 °C | 26.67 mm |
| Annual | 5.6 °C | 18.5 °C | 759.21 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| 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 | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |