Indianapolis, Indiana has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6.7 °C (low) to 17.1 °C (high). Annual precipitation averages 1116.3 Millimeters. Indianapolis 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. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -6.3 °C | 2.2 °C | 76.96 mm |
| February | -4.8 °C | 4.5 °C | 62.23 mm |
| March | 0 °C | 10.5 °C | 84.84 mm |
| April | 6.1 °C | 17.7 °C | 113.03 mm |
| May | 12.2 °C | 23 °C | 122.43 mm |
| June | 17.2 °C | 27.8 °C | 131.57 mm |
| July | 18.9 °C | 29.5 °C | 112.01 mm |
| August | 18.1 °C | 28.9 °C | 80.77 mm |
| September | 13.8 °C | 25.8 °C | 83.82 mm |
| October | 7.5 °C | 18.9 °C | 82.55 mm |
| November | 1.4 °C | 11.1 °C | 88.39 mm |
| December | -3.3 °C | 4.7 °C | 77.72 mm |
| Annual | 6.7 °C | 17.1 °C | 1116.32 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 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 |