Harrisville, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 38.5 °F (low) to 59.9 °F (high). Annual precipitation averages 44 Inches. Harrisville 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 | 17.3 °F | 34.8 °F | 3.17 in. |
| February | 18.5 °F | 38.0 °F | 2.54 in. |
| March | 25.7 °F | 46.9 °F | 3.27 in. |
| April | 36.1 °F | 60.0 °F | 3.92 in. |
| May | 46.3 °F | 70.4 °F | 3.96 in. |
| June | 55.2 °F | 78.4 °F | 4.78 in. |
| July | 59.0 °F | 82.4 °F | 4.63 in. |
| August | 57.5 °F | 81.2 °F | 3.83 in. |
| September | 50.8 °F | 74.9 °F | 3.98 in. |
| October | 40.1 °F | 62.5 °F | 3.37 in. |
| November | 31.3 °F | 50.1 °F | 3.31 in. |
| December | 23.6 °F | 39.3 °F | 3.25 in. |
| Annual | 38.5 °F | 59.9 °F | 44.01 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 |