Youngsville, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 37.3 °F (low) to 58.2 °F (high). Annual precipitation averages 46.1 Inches. Youngsville is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 16.5 °F | 32.5 °F | 3.39 in. |
| February | 16.6 °F | 35.0 °F | 2.49 in. |
| March | 23.5 °F | 44.0 °F | 3.17 in. |
| April | 34.0 °F | 58.0 °F | 3.93 in. |
| May | 44.7 °F | 69.8 °F | 4.03 in. |
| June | 53.8 °F | 77.3 °F | 4.58 in. |
| July | 57.7 °F | 81.5 °F | 4.84 in. |
| August | 56.5 °F | 80.2 °F | 4.03 in. |
| September | 50.1 °F | 73.6 °F | 4.03 in. |
| October | 39.8 °F | 61.0 °F | 4.16 in. |
| November | 31.1 °F | 47.9 °F | 3.67 in. |
| December | 23.6 °F | 37.1 °F | 3.76 in. |
| Annual | 37.3 °F | 58.2 °F | 46.08 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |