Last updated: June 24, 2025
In South Boston, United States, the average temperature in September is a pleasant 23°C (74°F). However, temperatures can range dramatically, dipping to a chilly 6°C (43°F) at their lowest and soaring up to a scorching 38°C (100°F) at their peak. Expect about 98 mm (3.9 in) of precipitation spread over 9 days, contributing to an average humidity level of 75%. Stay prepared for a mix of weather this month!
In September in South Boston, the average temperature is 23°C (74°F). Maximum temperatures can reach up to 38°C (100°F), while minimums can drop as low as 6°C (43°F). This range makes it essential to pack accordingly for your travels, ensuring you are prepared for both warm days and cooler nights.
In South Boston in September, the precipitation amount is 98 mm (3.9 in) spread over a duration of 9 days.
In South Boston in September, humidity is 75%. With an average temperature of 23°C (74°F), this humidity feels like a warm, heavy blanket wrapping around you, making it feel more sweltering than it actually is, which can be quite uncomfortable for traveling.
In South Boston in September, the maximum UV index is 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, you can check the Hourly UV Index in South Boston.
UV Risk Categories
Weather in South Boston varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in South Boston, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 5°C (41°F) | 73 mm (2.9 inches) | 84% | moderate |
| February Weather | 8°C (46°F) | 108 mm (4.2 inches) | 84% | high |
| March Weather | 11°C (51°F) | 72 mm (2.8 inches) | 84% | high |
| April Weather | 16°C (61°F) | 120 mm (4.7 inches) | 82% | very high |
| May Weather | 21°C (69°F) | 110 mm (4.3 inches) | 82% | extreme |
| June Weather | 24°C (76°F) | 92 mm (3.6 inches) | 83% | extreme |
| July Weather | 27°C (81°F) | 69 mm (2.7 inches) | 79% | very high |
| August Weather | 26°C (79°F) | 109 mm (4.3 inches) | 77% | very high |
| September Weather | 23°C (74°F) | 98 mm (3.9 inches) | 75% | very high |
| October Weather | 18°C (64°F) | 106 mm (4.2 inches) | 81% | very high |
| November Weather | 10°C (50°F) | 75 mm (3.0 inches) | 87% | moderate |
| December Weather | 7°C (45°F) | 96 mm (3.8 inches) | 85% | moderate |