Roann, Indiana has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5 °C (low) to 15.8 °C (high). Annual precipitation averages 1030.5 Millimeters. Roann is located in USDA Plant Hardiness Zone 6a. 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 | -7.8 °C | 0.6 °C | 67.31 mm |
| February | -6.6 °C | 2.7 °C | 55.88 mm |
| March | -1.8 °C | 8.8 °C | 69.34 mm |
| April | 3.9 °C | 15.9 °C | 94.74 mm |
| May | 10.2 °C | 22.2 °C | 112.27 mm |
| June | 15.6 °C | 27.1 °C | 123.19 mm |
| July | 17.3 °C | 28.7 °C | 109.22 mm |
| August | 16.2 °C | 27.9 °C | 98.3 mm |
| September | 12 °C | 24.8 °C | 82.04 mm |
| October | 5.7 °C | 17.8 °C | 75.18 mm |
| November | 0.2 °C | 9.8 °C | 80.52 mm |
| December | -4.6 °C | 3.2 °C | 62.48 mm |
| Annual | 5 °C | 15.8 °C | 1030.47 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |