Parker, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 4 °C (low) to 16.3 °C (high). Annual precipitation averages 1108.2 Millimeters. Parker 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 | -7.4 °C | 2 °C | 80.77 mm |
| February | -7.1 °C | 3.7 °C | 64.26 mm |
| March | -3.2 °C | 8.9 °C | 84.07 mm |
| April | 2.2 °C | 16.9 °C | 97.03 mm |
| May | 8.2 °C | 22.8 °C | 92.96 mm |
| June | 13.4 °C | 26.9 °C | 127.76 mm |
| July | 15.6 °C | 28.9 °C | 115.82 mm |
| August | 14.9 °C | 28.4 °C | 97.28 mm |
| September | 11.1 °C | 24.8 °C | 100.33 mm |
| October | 4.8 °C | 17.9 °C | 82.3 mm |
| November | -0.2 °C | 10.4 °C | 82.55 mm |
| December | -4.2 °C | 4.4 °C | 83.06 mm |
| Annual | 4 °C | 16.3 °C | 1108.19 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |