Williams, Indiana has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 43.3 °F (low) to 65.3 °F (high). Annual precipitation averages 49.9 Inches. Williams 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 21.6 °F | 39.5 °F | 3.7 in. |
| February | 24.4 °F | 44.5 °F | 3.15 in. |
| March | 32.2 °F | 54.4 °F | 4.17 in. |
| April | 42.2 °F | 66.4 °F | 5.32 in. |
| May | 52.7 °F | 75.4 °F | 5.86 in. |
| June | 61.5 °F | 83.4 °F | 5.0 in. |
| July | 64.6 °F | 86.6 °F | 4.45 in. |
| August | 62.6 °F | 85.9 °F | 3.39 in. |
| September | 55.1 °F | 80.2 °F | 3.58 in. |
| October | 43.1 °F | 68.5 °F | 3.55 in. |
| November | 33.3 °F | 55.0 °F | 4.04 in. |
| December | 26.0 °F | 43.7 °F | 3.72 in. |
| Annual | 43.3 °F | 65.3 °F | 49.93 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°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 |