Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
Frederiksted experiences peak temperatures, averaging a high-temperature of 84.2°F (29°C) during September and October.Heat index
September's average heat index is calculated to be a tropical 93.2°F (34°C). Take extra safety measures to prevent heat exhaustion and heat cramps. Heatstroke could follow lengthy activity.Heat index evaluations are typically in the context of light winds and shaded environments. Direct sunlight can cause a surge in the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'feels like', is calculated by taking the relative humidity value for a specific location and factoring it into the air temperature reading. Factors such as metabolic variation, pregnancy, and physical activity play a role in one's impression of weather. Direct sun rays can make one feel hotter, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values remain especially vital for babies and toddlers. Young ones often ignore the need to take a break and drink fluids. Thirst is a late-stage symptom of dehydration - hence, maintaining hydration, particularly during extended physical activities, is crucial.
Humidity
In September, the average relative humidity is 76%.Rainfall
In Frederiksted, in September, it is raining for 22.8 days, with typically 4.09" (104mm) of accumulated precipitation. Throughout the year, there are 254.5 rainfall days, and 29.49" (749mm) of precipitation is accumulated.Daylight
In Frederiksted, the average length of the day in September is 12h and 14min.On the first day of the month, sunrise is at 6:05 am and sunset at 6:33 pm. On the last day of September, sunrise is at 6:09 am and sunset at 6:08 pm AST.
Sunshine
The average sunshine in September is 8.9h.UV index
The months with the highest UV index are January through December, with an average maximum UV index of 7. The 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 threat to health from exposure to the Sun's UV radiation for ordinary individuals.Note: The maximum UV index, 7 during September, leads to the following recommendations:
Persist with precautions and heed sun safety advice. Prevention of sunburn is compulsory. 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. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection.
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Data Sources | Weather Forecasting & Climate
Frequently asked questions
What part of the year is the hottest?
How hot is September?
What is the average humidity in September in Frederiksted?
How much does it rain in September?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Frederiksted have in September?
What is the month with the highest UV index?
What is the month with the lowest UV index in Frederiksted?
How high is the UV index in September?
Average temperature in September
Frederiksted, VI
- Average high temperature in September: 84.2°F
The warmest months (with the highest average high temperature) are September and October (84.2°F).
The month with the lowest average high temperature is March (78.8°F).
- Average low temperature in September: 81.9°F
The month with the highest average low temperature is October (82.2°F).
The coldest month (with the lowest average low temperature) is March (76.6°F).
Average pressure in September
Frederiksted, VI
- Average pressure in September: 29.92"Hg
The months with the highest atmospheric pressure are January, February and June (30.01"Hg).
The months with the lowest atmospheric pressure are October and November (29.9"Hg).
Average wind speed in September
Frederiksted, VI
- Average wind speed in September: 11.3mph
The windiest month (with the highest average wind speed) is July (14.7mph).
The calmest month (with the lowest average wind speed) is October (11mph).
Average humidity in September
Frederiksted, VI
- Average humidity in September: 76%
The months with the highest relative humidity are May, June, July and August (78%).
The months with the lowest relative humidity are January, February, March and December (75%).
Average rainfall in September
Frederiksted, VI
- Average rainfall in September: 4.09"
The wettest month (with the highest rainfall) is August (4.17").
The driest month (with the least rainfall) is February (1.18").
Average rainfall days in September
Frederiksted, VI
- Average rainfall days in September: 22.8 days
The month with the highest number of rainy days is August (24.7 days).
The month with the least rainy days is February (16.7 days).
Average daylight in September /
Average sunshine in September
Frederiksted, VI
- Average daylight in September: 12h and 1min
The month with the longest days is June (Average daylight: 13h and 12min).
The month with the shortest days is December (Average daylight: 11h and 6min).
- Average sunshine in September: 8h and 5min
The month with the most sunshine is June (Average sunshine: 10h and 30min).
The month with the least sunshine is December (Average sunshine: 6h and 24min).
Average sunshine days in September
Frederiksted, VI
- Average sunshine days in September: 3.7 days
The month with the most sunshine days is March (7.6 days).
The month with the least sunshine days is August (1.8 days).
Average UV index in September
Frederiksted, VI
- Average UV index in September: 7
The months with the highest UV index are January, February, March, April, May, June, July, August, September, October, November and December (UV index 7).
The months with the lowest UV index are January, February, March, April, May, June, July, August, September, October, November and December (UV index 7).
Average cloud cover in September
Frederiksted, VI
- Average cloud cover in September: 35
The months with the most cloud cover are May and July (Cloud cover 40).
The month with the least cloud cover is February (Cloud cover 33).
Average visibility in September
Frederiksted, VI
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Frederiksted, United States Virgin Islands, USA
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