Milroy, Indiana has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.8 °C (low) to 16.8 °C (high). Annual precipitation averages 1148.9 Millimeters. Milroy is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -6.7 °C | 2.3 °C | 81.03 mm |
| February | -5.2 °C | 4.6 °C | 66.8 mm |
| March | -0.7 °C | 10.3 °C | 92.2 mm |
| April | 5.2 °C | 17.3 °C | 120.65 mm |
| May | 11.2 °C | 22.8 °C | 128.52 mm |
| June | 16.1 °C | 27.4 °C | 130.05 mm |
| July | 17.8 °C | 29 °C | 105.16 mm |
| August | 16.7 °C | 28.4 °C | 86.36 mm |
| September | 12.4 °C | 25.5 °C | 81.03 mm |
| October | 6.2 °C | 18.8 °C | 80.26 mm |
| November | 0.5 °C | 11 °C | 89.41 mm |
| December | -3.8 °C | 4.7 °C | 87.38 mm |
| Annual | 5.8 °C | 16.8 °C | 1148.85 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 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 | Dfa - Humid Continental Hot Summers With Year Around Precipitation |