Sligo, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 3.4 °C (low) to 15.5 °C (high). Annual precipitation averages 1164.3 Millimeters. Sligo is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.9 °C | 1.4 °C | 87.88 mm |
| February | -7.6 °C | 3.1 °C | 65.02 mm |
| March | -3.7 °C | 8.3 °C | 85.34 mm |
| April | 1.8 °C | 15.9 °C | 100.08 mm |
| May | 7.5 °C | 21.9 °C | 97.54 mm |
| June | 12.6 °C | 26.1 °C | 128.52 mm |
| July | 14.8 °C | 27.9 °C | 124.71 mm |
| August | 14.2 °C | 27.6 °C | 104.14 mm |
| September | 10.3 °C | 23.7 °C | 104.14 mm |
| October | 4.3 °C | 16.8 °C | 87.38 mm |
| November | -0.8 °C | 9.9 °C | 90.17 mm |
| December | -4.6 °C | 3.8 °C | 89.41 mm |
| Annual | 3.4 °C | 15.5 °C | 1164.33 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°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 |