Charlotte Amalie
United States Virgin Islands, USA
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Charlotte Amalie, VI

An aerial night view of the Charlotte Amalie Harbour within the United States Virgin Islands
An aerial night view of the Charlotte Amalie Harbour within the United States Virgin Islands
September, the first month of the autumn, in Charlotte Amalie, is also a moderately hot month, with temperature in the range of an average low of 81.3°F (27.4°C) and an average high of 84°F (28.9°C).

Temperature

The warmest month is September, with an average high-temperature of 84°F (28.9°C) and an average low-temperature of 81.3°F (27.4°C).

Heat index

The average heat index is evaluated at a hot 92.8°F (33.8°C). Take special precautions - heat exhaustion and heat cramps are expected. Heatstroke may occur with lengthy activity.
Take into consideration that the heat index values are calculated for shade and light wind conditions. With the exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel', 'apparent temperature', 'feels like', or 'felt air temperature', is calculated by taking the relative humidity value for a specific location and factoring it into the air temperature reading. Additional factors like activity, wind, differences in body mass, height, and shape, and metabolic differences affect individual temperature impact. Be aware that direct exposure to sunlight increases heat impact, and may raise the heat index additionally, by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it is vital to remain hydrated, particularly during prolonged physical activities.

Humidity

In September, the average relative humidity in Charlotte Amalie is 77%.

Rainfall

September is the month with the most rainfall in Charlotte Amalie, United States Virgin Islands. Rain falls for 22.2 days and accumulates 4.45" (113mm) of precipitation.

Ocean temperature

September is the month with the warmest seawater, with an average ocean temperature of 84.9°F (29.4°C).
Note: For swimming, diving, and other water activities, temperatures between 77°F (25°C) and 84.2°F (29°C) are perceived as very enjoyable and pleasurable for prolonged periods without feeling uncomfortable.

Daylight

The average length of the day in September is 12.2h.

Sunshine

The average sunshine in Charlotte Amalie is 8.7h.

UV index

Months with the highest UV index in Charlotte Amalie are January through December, with an average maximum UV index of 7. Months with the lowest UV index are January through December, with an average maximum UV index of 7. A UV Index reading of 6 to 7 represents a high health vulnerability from the exposure to the Sun's UV radiation for the ordinary person.
Note: The average daily UV index of 7 transform into the following instructions:
Take precautions against overexposure. Fair-skinned people may get burned in less than 20 minutes. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. Beware! The reflection of water and sand dramatically increases exposure to the UV rays.

What is the warmest month in Charlotte Amalie?

The warmest month in Charlotte Amalie, United States Virgin Islands, is September, with an average high-temperature of 84°F (28.9°C) and an average low-temperature of 81.3°F (27.4°C).

What is the temperature in September in Charlotte Amalie?

In Charlotte Amalie, United States Virgin Islands, in September, the average high-temperature is 84°F (28.9°C), and the average low-temperature is 81.3°F (27.4°C). In September, the average heat index (a.k.a. 'real feel', 'apparent temperature'), that combines air temperature and relative humidity, is appraised at 92.8°F (33.8°C).

What is the average humidity in September in Charlotte Amalie?

In Charlotte Amalie, United States Virgin Islands, the average relative humidity in September is 77%.

How many days does it rain in September in Charlotte Amalie?

In Charlotte Amalie, in September, it is raining for 22.2 days, with typically 4.45" (113mm) of accumulated precipitation.

What is the wettest month in Charlotte Amalie?

September is the month with the most rainfall. Rain falls for 22.2 days and accumulates 4.45" (113mm) of precipitation.

When is the ocean warmest in Charlotte Amalie?

September is the month with the warmest seawater, with an average ocean temperature of 84.9°F (29.4°C).

How warm is the water in September in Charlotte Amalie?

In Charlotte Amalie, United States Virgin Islands, in September, the average water temperature is 84.9°F (29.4°C). For any water activity, surface water temperatures between 77°F (25°C) and 84.2°F (29°C) are considered as excellent and extremely pleasant for lengthened periods.

What is the average length of the day in September in Charlotte Amalie?

The average length of the day in September in Charlotte Amalie, United States Virgin Islands, is 12.2h.

How long on average sun shines in September in Charlotte Amalie?

In Charlotte Amalie, the average sunshine in September is 8.7h.

What is the month with the highest UV index in Charlotte Amalie?

January through December, with an average maximum UV index of 7, are months with the highest UV index in Charlotte Amalie, United States Virgin Islands.

What are the months with the lowest UV index in Charlotte Amalie?

January through December, with an average maximum UV index of 7, are months with the lowest UV index in Charlotte Amalie, United States Virgin Islands.

What is the UV index reading in September in Charlotte Amalie?

In Charlotte Amalie, United States Virgin Islands, the average daily maximum UV index in September is 7. A UV Index reading of 6 to 7 represents a high health threat from unsafe exposure to the Sun's UV rays.
Average temperature in September - Charlotte Amalie, VI
  • Average high temperature in September: 28.9°C

The warmest month (with the highest average high temperature) is September (28.9°C).
The month with the lowest average high temperature is March (25.8°C).

  • Average low temperature in September: 27.4°C

The month with the highest average low temperature is October (27.5°C).
The coldest month (with the lowest average low temperature) is March (24.3°C).

Average humidity in September - Charlotte Amalie, VI
  • Average humidity in September: 77%

Months with the highest relative humidity are May, June, July and August (78%).
Months with the lowest relative humidity are January, February, March, October, November and December (75%).

Average rainfall in September - Charlotte Amalie, VI
  • Average rainfall in September: 113mm

The wettest month (with the highest rainfall) is September (113mm).
The driest month (with the lowest rainfall) is February (31mm).

Average rainfall days in September - Charlotte Amalie, VI
  • Average rainfall days in September: 22.2 days

The month with the highest number of rainy days is November (25.5 days).
Months with the lowest number of rainy days are February, March and June (18.2 days).

Average sea temperature in September - Charlotte Amalie, VI
  • Average sea temperature in September: 29.4°C

The best month for swimming (with the highest average sea temperature) is September (29.4°C).
The coldest month (with the lowest average sea temperature) is February (25.9°C).

Average daylight in September / Average sunshine in September - Charlotte Amalie, VI
  • Average daylight in September: 12.2h

The month with the longest days is June (Average daylight: 13.2h).
The month with shortest days is December (Average daylight: 11h).

  • Average sunshine in September: 8.7h

The month with most sunshine is June (Average sunshine: 10.5h).
Months with least sunshine are November and December (Average sunshine: 6.5).

Average UV index in September - Charlotte Amalie, VI
  • Average UV index in September: 7

Months with the highest UV index are January, February, March, April, May, June, July, August, September, October, November and December (UV index 7).
Months with the lowest UV index are January, February, March, April, May, June, July, August, September, October, November and December (UV index 7).