Union Dale, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 35.3 °F (low) to 54.7 °F (high). Annual precipitation averages 47.8 Inches. Union Dale is located in USDA Plant Hardiness Zone 5b. 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 | 13.1 °F | 29.7 °F | 3.51 in. |
| February | 13.8 °F | 32.3 °F | 2.74 in. |
| March | 21.3 °F | 40.6 °F | 3.33 in. |
| April | 32.6 °F | 54.0 °F | 4.0 in. |
| May | 43.5 °F | 65.5 °F | 4.58 in. |
| June | 52.9 °F | 73.5 °F | 5.2 in. |
| July | 56.9 °F | 77.9 °F | 4.58 in. |
| August | 55.6 °F | 76.2 °F | 3.95 in. |
| September | 48.2 °F | 69.5 °F | 4.39 in. |
| October | 37.3 °F | 57.3 °F | 4.66 in. |
| November | 28.2 °F | 45.3 °F | 3.16 in. |
| December | 20.1 °F | 34.7 °F | 3.66 in. |
| Annual | 35.3 °F | 54.7 °F | 47.76 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |