Bethany, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 36.6 °F (low) to 56.6 °F (high). Annual precipitation averages 47 Inches. Bethany is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 14.1 °F | 31.5 °F | 3.53 in. |
| February | 15.1 °F | 34.1 °F | 2.71 in. |
| March | 22.8 °F | 42.7 °F | 3.37 in. |
| April | 33.4 °F | 56.0 °F | 3.86 in. |
| May | 44.9 °F | 67.4 °F | 4.08 in. |
| June | 54.2 °F | 75.3 °F | 4.95 in. |
| July | 58.5 °F | 79.7 °F | 4.42 in. |
| August | 57.2 °F | 78.0 °F | 3.98 in. |
| September | 50.0 °F | 71.3 °F | 4.55 in. |
| October | 38.4 °F | 59.2 °F | 4.42 in. |
| November | 29.2 °F | 47.5 °F | 3.17 in. |
| December | 21.0 °F | 36.3 °F | 3.99 in. |
| Annual | 36.6 °F | 56.6 °F | 47.03 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 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 |