James City, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 1.5 °C (low) to 12.8 °C (high). Annual precipitation averages 1227.1 Millimeters. James City is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.2 °C | -1.1 °C | 96.01 mm |
| February | -10 °C | 0.3 °C | 69.6 mm |
| March | -5.8 °C | 5.4 °C | 88.14 mm |
| April | 0.1 °C | 12.9 °C | 107.19 mm |
| May | 5.8 °C | 19.3 °C | 112.78 mm |
| June | 10.6 °C | 23.3 °C | 120.4 mm |
| July | 12.8 °C | 25.3 °C | 118.87 mm |
| August | 11.9 °C | 24.6 °C | 109.98 mm |
| September | 8.4 °C | 20.9 °C | 102.36 mm |
| October | 2.7 °C | 14.2 °C | 102.11 mm |
| November | -1.9 °C | 7.4 °C | 98.3 mm |
| December | -6.4 °C | 1.4 °C | 101.35 mm |
| Annual | 1.5 °C | 12.8 °C | 1227.09 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |