Sunman, Indiana has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6.2 °C (low) to 17.2 °C (high). Annual precipitation averages 1188 Millimeters. Sunman 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. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -6 °C | 3.1 °C | 87.63 mm |
| February | -4.9 °C | 5.4 °C | 71.88 mm |
| March | -0.1 °C | 10.9 °C | 98.81 mm |
| April | 5.7 °C | 17.9 °C | 124.46 mm |
| May | 11.4 °C | 22.8 °C | 137.92 mm |
| June | 16.2 °C | 27.2 °C | 121.92 mm |
| July | 17.9 °C | 28.9 °C | 104.39 mm |
| August | 17.1 °C | 28.6 °C | 89.92 mm |
| September | 12.8 °C | 25.4 °C | 80.77 mm |
| October | 6.7 °C | 18.9 °C | 86.87 mm |
| November | 0.7 °C | 11.7 °C | 84.84 mm |
| December | -3.3 °C | 5.4 °C | 98.55 mm |
| Annual | 6.2 °C | 17.2 °C | 1187.96 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°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 |