Sylvania, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.1 °C (low) to 14 °C (high). Annual precipitation averages 977.1 Millimeters. Sylvania 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 | -9.9 °C | 0 °C | 66.29 mm |
| February | -9.5 °C | 1.5 °C | 49.78 mm |
| March | -5.6 °C | 6.1 °C | 75.44 mm |
| April | 0.3 °C | 13.6 °C | 85.09 mm |
| May | 6.4 °C | 20.2 °C | 88.14 mm |
| June | 11.4 °C | 24.6 °C | 99.31 mm |
| July | 13.8 °C | 27 °C | 89.15 mm |
| August | 13.1 °C | 26.2 °C | 88.9 mm |
| September | 9.2 °C | 22.4 °C | 104.9 mm |
| October | 3.3 °C | 15.5 °C | 90.42 mm |
| November | -1.7 °C | 8.4 °C | 70.87 mm |
| December | -6 °C | 2.7 °C | 68.83 mm |
| Annual | 2.1 °C | 14 °C | 977.12 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 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 |