Corydon, Indiana has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 7.9 °C (low) to 19.6 °C (high). Annual precipitation averages 1260.1 Millimeters. Corydon is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -3.9 °C | 5.9 °C | 93.73 mm |
| February | -2.4 °C | 8.5 °C | 89.41 mm |
| March | 1.8 °C | 13.9 °C | 119.13 mm |
| April | 7.3 °C | 20.3 °C | 127.76 mm |
| May | 12.9 °C | 24.9 °C | 134.11 mm |
| June | 17.7 °C | 29.2 °C | 119.63 mm |
| July | 19.7 °C | 30.9 °C | 105.41 mm |
| August | 18.8 °C | 30.6 °C | 79.5 mm |
| September | 14.6 °C | 27.4 °C | 95.5 mm |
| October | 8.1 °C | 21.3 °C | 92.46 mm |
| November | 2.3 °C | 14 °C | 94.23 mm |
| December | -1.6 °C | 8 °C | 109.22 mm |
| Annual | 7.9 °C | 19.6 °C | 1260.09 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |