Last updated: June 24, 2025
In South Williamsport, United States, the average temperature in September hovers around 18°C (65°F), providing a pleasant backdrop for various activities. Expect temperatures to range from a cool 2°C (35°F) to a warm 32°C (90°F). During this month, the region experiences an average precipitation of 121 mm (4.8 in) spread over 10 days, contributing to an overall humidity level of 66%. Plan accordingly to enjoy the best of what this enchanting destination has to offer!
In September in South Williamsport, the average temperature is 18°C (65°F). Maximums can reach 32°C (90°F) and minimums can be as low as 2°C (35°F). This diverse temperature range makes it essential for travelers to pack for both warm and cool conditions.
In South Williamsport in September, the precipitation amount is 121 mm (4.8 in) spread over a period of 10 days.
In South Williamsport in September humidity is 66%. With an average temperature of 18°C (65°F), this humidity feels like a warm embrace, making travel comfortable yet slightly sticky, perfect for leisurely strolls but requiring light, breathable clothing to fully enjoy the experience.
In South Williamsport in September, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in South Williamsport.
UV Risk Categories
Weather in South Williamsport varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in South Williamsport, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -2°C (29°F) | 74 mm (2.9 inches) | 87% | moderate |
| February Weather | -1°C (31°F) | 99 mm (3.9 inches) | 85% | moderate |
| March Weather | 3°C (38°F) | 89 mm (3.5 inches) | 85% | high |
| April Weather | 9°C (49°F) | 115 mm (4.5 inches) | 83% | very high |
| May Weather | 15°C (60°F) | 137 mm (5.4 inches) | 75% | very high |
| June Weather | 20°C (68°F) | 105 mm (4.1 inches) | 73% | very high |
| July Weather | 23°C (74°F) | 146 mm (5.8 inches) | 65% | very high |
| August Weather | 22°C (72°F) | 113 mm (4.4 inches) | 62% | very high |
| September Weather | 18°C (65°F) | 121 mm (4.8 inches) | 66% | very high |
| October Weather | 13°C (55°F) | 135 mm (5.3 inches) | 79% | high |
| November Weather | 5°C (40°F) | 97 mm (3.8 inches) | 87% | moderate |
| December Weather | 1°C (34°F) | 94 mm (3.7 inches) | 85% | low |