James City, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 34.7 °F (low) to 55.1 °F (high). Annual precipitation averages 48.3 Inches. 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 | 13.6 °F | 30.1 °F | 3.78 in. |
| February | 14.0 °F | 32.6 °F | 2.74 in. |
| March | 21.6 °F | 41.7 °F | 3.47 in. |
| April | 32.2 °F | 55.2 °F | 4.22 in. |
| May | 42.5 °F | 66.7 °F | 4.44 in. |
| June | 51.1 °F | 74.0 °F | 4.74 in. |
| July | 55.0 °F | 77.6 °F | 4.68 in. |
| August | 53.5 °F | 76.2 °F | 4.33 in. |
| September | 47.2 °F | 69.7 °F | 4.03 in. |
| October | 36.8 °F | 57.6 °F | 4.02 in. |
| November | 28.5 °F | 45.3 °F | 3.87 in. |
| December | 20.4 °F | 34.6 °F | 3.99 in. |
| Annual | 34.7 °F | 55.1 °F | 48.31 in. |
| 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 : -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 |