Milroy, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 39.7 °F (low) to 60.7 °F (high). Annual precipitation averages 40 Inches. Milroy is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 19.0 °F | 35.3 °F | 2.96 in. |
| February | 20.1 °F | 38.7 °F | 2.34 in. |
| March | 27.0 °F | 47.7 °F | 3.37 in. |
| April | 37.2 °F | 61.2 °F | 3.32 in. |
| May | 47.7 °F | 71.6 °F | 3.75 in. |
| June | 56.9 °F | 79.5 °F | 3.49 in. |
| July | 60.9 °F | 83.8 °F | 3.38 in. |
| August | 59.3 °F | 82.1 °F | 3.24 in. |
| September | 52.0 °F | 75.0 °F | 4.34 in. |
| October | 40.9 °F | 63.1 °F | 3.46 in. |
| November | 31.5 °F | 51.0 °F | 3.07 in. |
| December | 24.4 °F | 39.8 °F | 3.29 in. |
| Annual | 39.7 °F | 60.7 °F | 40.01 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |