Milltown, Indiana has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 43.4 °F (low) to 66.4 °F (high). Annual precipitation averages 52.4 Inches. Milltown is located in USDA Plant Hardiness Zone 6b. 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 | 22.3 °F | 41.4 °F | 3.78 in. |
| February | 25.0 °F | 46.3 °F | 3.63 in. |
| March | 32.2 °F | 55.9 °F | 4.86 in. |
| April | 42.2 °F | 67.7 °F | 5.53 in. |
| May | 52.2 °F | 76.2 °F | 5.53 in. |
| June | 61.4 °F | 83.9 °F | 5.1 in. |
| July | 64.6 °F | 86.8 °F | 4.61 in. |
| August | 62.6 °F | 86.3 °F | 3.47 in. |
| September | 54.9 °F | 80.7 °F | 3.81 in. |
| October | 43.3 °F | 69.6 °F | 3.83 in. |
| November | 33.4 °F | 56.3 °F | 3.97 in. |
| December | 26.5 °F | 45.3 °F | 4.3 in. |
| Annual | 43.4 °F | 66.4 °F | 52.42 in. |
| 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 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |