Chesterton, Indiana has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.5 °C (low) to 15.1 °C (high). Annual precipitation averages 1019.6 Millimeters. Chesterton 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. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.7 °C | 0.2 °C | 61.47 mm |
| February | -6.3 °C | 2.2 °C | 56.39 mm |
| March | -1.7 °C | 7.8 °C | 58.17 mm |
| April | 3.9 °C | 14.6 °C | 91.44 mm |
| May | 9.6 °C | 20.7 °C | 106.17 mm |
| June | 15.1 °C | 25.8 °C | 111.76 mm |
| July | 17.9 °C | 28.1 °C | 107.19 mm |
| August | 17.4 °C | 27.2 °C | 103.89 mm |
| September | 13.5 °C | 24.1 °C | 92.96 mm |
| October | 6.9 °C | 17.3 °C | 103.12 mm |
| November | 1.1 °C | 9.7 °C | 70.1 mm |
| December | -4.3 °C | 3.1 °C | 56.9 mm |
| Annual | 5.5 °C | 15.1 °C | 1019.56 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| 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 |