Foundryville, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 40.8 °F (low) to 61.9 °F (high). Annual precipitation averages 44.9 Inches. Foundryville 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 | 19.6 °F | 36.4 °F | 3.0 in. |
| February | 21.0 °F | 39.2 °F | 2.32 in. |
| March | 28.2 °F | 48.0 °F | 3.1 in. |
| April | 38.4 °F | 62.1 °F | 3.85 in. |
| May | 48.6 °F | 73.0 °F | 3.92 in. |
| June | 57.8 °F | 80.7 °F | 4.79 in. |
| July | 62.1 °F | 85.4 °F | 4.73 in. |
| August | 60.5 °F | 83.5 °F | 4.26 in. |
| September | 53.4 °F | 76.6 °F | 4.9 in. |
| October | 42.0 °F | 64.4 °F | 3.84 in. |
| November | 32.9 °F | 51.7 °F | 2.99 in. |
| December | 25.5 °F | 41.2 °F | 3.19 in. |
| Annual | 40.8 °F | 61.9 °F | 44.89 in. |
| 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 : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |