September weather forecast
Saint John, VI

Despite heading towards the tail end of summer, September in Saint John brings no reprieve from the warmth. The tropical maritime climate is at its zenith during this period, with plenty of sun-soaked days to enjoy. The high point featuring September weather is the substantial increase in rainfall, registering a notable 5.6" (142mm). Locals and visitors can expect an interplay of hot sunny days and refreshing evening showers.

Temperature

The warmest months are August and September, with an average high-temperature of 87.8°F (31°C).

Rainfall

In Saint John, in September, during 16 rainfall days, 5.63" (143mm) of precipitation is typically accumulated. Throughout the year, in Saint John, there are 156 rainfall days, and 49.69" (1262mm) of precipitation is accumulated.

Ocean temperature

September and October, with an average ocean temperature of 84.2°F (29°C), are months with the warmest seawater.
Note: For swimming, diving, and similar activities, the water temperatures between 77°F (25°C) and 84.2°F (29°C) are considered delightful, allowing for extended periods of enjoyment without discomfort.

Daylight

The average length of the day in September in Saint John, United States Virgin Islands, is 12h and 14min.
On the first day of the month, sunrise is at 6:04 am and sunset at 6:32 pm. On the last day of September, sunrise is at 6:09 am and sunset at 6:08 pm AST.

Sunshine

In Saint John, the average sunshine in September is 8h.

UV index

March through September, with an average maximum UV index of 12, are months with the highest UV index. A UV Index value of 11, and more, symbolizes an ultimate health vulnerability from unprotected exposure to Sun's UV rays for the average person.
Note: In September, the maximum UV index of 12 translates into these guidelines:
Take all required precautions, as unprotected skin and eyes can burn in minutes. Attempt to stay under shade and limit exposure to the Sun between 10 a.m. and 4 p.m., when UV radiation is at its peak. Remember, devices such as parasols or canopies might not provide complete sun protection. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance. Apply and frequently reapply a broad-spectrum SPF 30+ sunscreen after every two hours, or immediately after a swim or outdoor exercise. Stay aware! UV radiation is magnified when reflecting off sand and water.