Annville, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6.1 °C (low) to 16.9 °C (high). Annual precipitation averages 1171.7 Millimeters. Annville is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.8 °C | 3.1 °C | 80.52 mm |
| February | -5.1 °C | 4.7 °C | 62.48 mm |
| March | -0.8 °C | 9.7 °C | 95 mm |
| April | 4.9 °C | 16.8 °C | 94.23 mm |
| May | 10.5 °C | 22.4 °C | 98.3 mm |
| June | 15.7 °C | 27.2 °C | 112.52 mm |
| July | 18.1 °C | 29.8 °C | 118.36 mm |
| August | 17.2 °C | 28.7 °C | 105.92 mm |
| September | 13.2 °C | 24.9 °C | 124.46 mm |
| October | 6.8 °C | 18.2 °C | 107.44 mm |
| November | 1.3 °C | 11.7 °C | 81.79 mm |
| December | -2.8 °C | 5.8 °C | 90.68 mm |
| Annual | 6.1 °C | 16.9 °C | 1171.7 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |