Winchester, Indiana has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 41.2 °F (low) to 60.6 °F (high). Annual precipitation averages 40.5 Inches. Winchester 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 | 18.0 °F | 33.7 °F | 2.74 in. |
| February | 20.5 °F | 37.7 °F | 2.18 in. |
| March | 29.4 °F | 48.2 °F | 3.16 in. |
| April | 39.8 °F | 61.2 °F | 4.07 in. |
| May | 51.1 °F | 71.7 °F | 4.31 in. |
| June | 60.4 °F | 80.2 °F | 4.64 in. |
| July | 62.7 °F | 83.0 °F | 4.0 in. |
| August | 60.7 °F | 81.8 °F | 3.47 in. |
| September | 53.4 °F | 76.5 °F | 3.11 in. |
| October | 42.7 °F | 64.2 °F | 3.02 in. |
| November | 32.3 °F | 50.3 °F | 3.19 in. |
| December | 23.8 °F | 38.4 °F | 2.64 in. |
| Annual | 41.2 °F | 60.6 °F | 40.53 in. |
| 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 : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |