Guys Mills, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 3.7 °C (low) to 14 °C (high). Annual precipitation averages 1212.8 Millimeters. Guys Mills 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -8.3 °C | 0.2 °C | 92.2 mm |
| February | -7.9 °C | 1.6 °C | 67.56 mm |
| March | -3.8 °C | 6.5 °C | 87.12 mm |
| April | 2.3 °C | 13.8 °C | 105.41 mm |
| May | 8.2 °C | 19.9 °C | 105.66 mm |
| June | 13.1 °C | 24.3 °C | 127.25 mm |
| July | 15.2 °C | 26.4 °C | 122.94 mm |
| August | 14.4 °C | 25.8 °C | 101.6 mm |
| September | 10.7 °C | 22.3 °C | 108.71 mm |
| October | 5.1 °C | 15.6 °C | 105.41 mm |
| November | -0.1 °C | 8.8 °C | 92.46 mm |
| December | -4.6 °C | 2.7 °C | 96.52 mm |
| Annual | 3.7 °C | 14 °C | 1212.84 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| 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 |