Last updated: June 24, 2025
In September, the average temperature in Southampton, United States is a pleasant 18°C (65°F). However, be prepared for a range, as temperatures can dip to a minimum of 2°C (36°F) and soar up to a maximum of 33°C (92°F). Expect about 112 mm (4.4 in) of precipitation over 8 days, accompanied by an average humidity of 72%.
In September, in Southampton, the average temperature is 18°C (65°F). The maximum can reach 33°C (92°F), while the minimum can be as low as 2°C (36°F). This temperature range makes Southampton an ideal destination for travelers seeking both warm days and cool nights.
In Southampton in September, the total precipitation amount is 112 mm (4.4 in) spread over 8 days.
In Southampton in September humidity is 72%. With an average temperature of 18°C (65°F), this humidity feels like a warm, sticky embrace, making traveling somewhat uncomfortable as the air clings to your skin and the heat can be stifling, yet it's perfect for enjoying leisurely strolls under the shade.
In Southampton 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 Southampton.
UV Risk Categories
Weather in Southampton varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Southampton, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -2°C (28°F) | 79 mm (3.1 inches) | 89% | moderate |
| February Weather | -1°C (31°F) | 97 mm (3.8 inches) | 88% | moderate |
| March Weather | 2°C (36°F) | 85 mm (3.4 inches) | 86% | high |
| April Weather | 8°C (48°F) | 144 mm (5.7 inches) | 84% | very high |
| May Weather | 15°C (59°F) | 109 mm (4.3 inches) | 76% | very high |
| June Weather | 20°C (68°F) | 89 mm (3.5 inches) | 72% | very high |
| July Weather | 23°C (73°F) | 158 mm (6.2 inches) | 66% | very high |
| August Weather | 22°C (72°F) | 106 mm (4.2 inches) | 64% | very high |
| September Weather | 18°C (65°F) | 112 mm (4.4 inches) | 72% | very high |
| October Weather | 12°C (54°F) | 156 mm (6.2 inches) | 81% | high |
| November Weather | 5°C (41°F) | 97 mm (3.8 inches) | 87% | moderate |
| December Weather | 0°C (32°F) | 123 mm (4.8 inches) | 84% | low |