Derry, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 40.3 °F (low) to 60.8 °F (high). Annual precipitation averages 50.1 Inches. Derry is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 19.9 °F | 36.5 °F | 3.95 in. |
| February | 21.0 °F | 39.5 °F | 3.17 in. |
| March | 28.0 °F | 48.4 °F | 3.92 in. |
| April | 38.1 °F | 61.5 °F | 4.29 in. |
| May | 48.3 °F | 71.3 °F | 4.78 in. |
| June | 56.9 °F | 78.6 °F | 5.1 in. |
| July | 61.0 °F | 82.3 °F | 5.26 in. |
| August | 59.4 °F | 81.4 °F | 4.05 in. |
| September | 52.5 °F | 75.0 °F | 4.43 in. |
| October | 41.1 °F | 63.2 °F | 3.52 in. |
| November | 31.9 °F | 51.2 °F | 3.75 in. |
| December | 25.2 °F | 40.9 °F | 3.84 in. |
| Annual | 40.3 °F | 60.8 °F | 50.06 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| 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 | Dfa - Humid Continental Hot Summers With Year Around Precipitation |