Glenshaw, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.9 °C (low) to 16.5 °C (high). Annual precipitation averages 1056.6 Millimeters. Glenshaw is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.8 °C | 2.7 °C | 84.33 mm |
| February | -5.1 °C | 4.3 °C | 66.29 mm |
| March | -1.3 °C | 9.4 °C | 80.26 mm |
| April | 4.6 °C | 17.1 °C | 89.15 mm |
| May | 10.4 °C | 22.4 °C | 99.06 mm |
| June | 15.3 °C | 26.8 °C | 108.71 mm |
| July | 17.6 °C | 28.8 °C | 108.2 mm |
| August | 16.8 °C | 28.2 °C | 89.15 mm |
| September | 12.9 °C | 24.6 °C | 94.23 mm |
| October | 6.6 °C | 17.8 °C | 78.49 mm |
| November | 1.3 °C | 10.9 °C | 76.45 mm |
| December | -2.8 °C | 5.2 °C | 82.3 mm |
| Annual | 5.9 °C | 16.5 °C | 1056.62 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |