Westover, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 3.6 °C (low) to 15.1 °C (high). Annual precipitation averages 1132.9 Millimeters. Westover 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. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.8 °C | 1.2 °C | 82.8 mm |
| February | -7.3 °C | 2.8 °C | 63.5 mm |
| March | -3.4 °C | 7.8 °C | 91.69 mm |
| April | 2.4 °C | 15.4 °C | 97.03 mm |
| May | 7.9 °C | 21.1 °C | 99.57 mm |
| June | 12.9 °C | 25.3 °C | 113.54 mm |
| July | 15.3 °C | 27.6 °C | 112.27 mm |
| August | 14.3 °C | 26.8 °C | 107.19 mm |
| September | 10.6 °C | 23.1 °C | 104.65 mm |
| October | 4.3 °C | 16.4 °C | 88.65 mm |
| November | -0.8 °C | 9.6 °C | 85.6 mm |
| December | -4.7 °C | 3.6 °C | 86.36 mm |
| Annual | 3.6 °C | 15.1 °C | 1132.85 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |