Williamsport, Indiana has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 41.7 °F (low) to 61.7 °F (high). Annual precipitation averages 40 Inches. Williamsport 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 | 17.7 °F | 33.5 °F | 2.37 in. |
| February | 20.6 °F | 38.0 °F | 2.06 in. |
| March | 29.9 °F | 49.6 °F | 2.81 in. |
| April | 40.6 °F | 62.6 °F | 4.12 in. |
| May | 52.0 °F | 73.5 °F | 4.38 in. |
| June | 61.3 °F | 81.8 °F | 4.86 in. |
| July | 63.8 °F | 84.3 °F | 4.29 in. |
| August | 61.6 °F | 82.9 °F | 3.42 in. |
| September | 54.1 °F | 78.4 °F | 2.88 in. |
| October | 42.8 °F | 65.9 °F | 3.18 in. |
| November | 32.5 °F | 50.9 °F | 3.14 in. |
| December | 23.5 °F | 38.6 °F | 2.44 in. |
| Annual | 41.7 °F | 61.7 °F | 39.95 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 5b : -15°F to -10°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |