South Williamsport, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 40.6 °F (low) to 61.4 °F (high). Annual precipitation averages 43.6 Inches. South Williamsport is located in USDA Plant Hardiness Zone 6b. 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 | 19.3 °F | 35.5 °F | 3.09 in. |
| February | 20.4 °F | 38.7 °F | 2.36 in. |
| March | 27.8 °F | 48.2 °F | 3.24 in. |
| April | 38.1 °F | 61.7 °F | 3.59 in. |
| May | 48.5 °F | 72.6 °F | 4.07 in. |
| June | 57.6 °F | 80.7 °F | 4.0 in. |
| July | 61.9 °F | 85.1 °F | 4.4 in. |
| August | 60.5 °F | 83.2 °F | 4.02 in. |
| September | 53.1 °F | 76.2 °F | 4.65 in. |
| October | 41.9 °F | 63.8 °F | 3.97 in. |
| November | 32.5 °F | 51.2 °F | 2.88 in. |
| December | 25.3 °F | 40.1 °F | 3.36 in. |
| Annual | 40.6 °F | 61.4 °F | 43.63 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 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |