Marion, Indiana has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.1 °C (low) to 15.8 °C (high). Annual precipitation averages 1049 Millimeters. Marion 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 | 68.58 mm |
| February | -6.5 °C | 2.7 °C | 56.64 mm |
| March | -1.7 °C | 8.9 °C | 76.45 mm |
| April | 4.1 °C | 16.1 °C | 105.16 mm |
| May | 10.3 °C | 22.2 °C | 115.82 mm |
| June | 15.8 °C | 26.9 °C | 117.86 mm |
| July | 17.4 °C | 28.6 °C | 103.63 mm |
| August | 16.2 °C | 27.8 °C | 93.73 mm |
| September | 12.1 °C | 24.9 °C | 83.82 mm |
| October | 5.8 °C | 17.9 °C | 78.99 mm |
| November | 0.3 °C | 9.9 °C | 82.55 mm |
| December | -4.6 °C | 3.4 °C | 65.79 mm |
| Annual | 5.1 °C | 15.8 °C | 1049.02 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| 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 |