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 sea temperature 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
The unfolding of September shows an average high-temperature of a still warm 84.6°F (29.2°C), indicating a slight variance from August's 85.5°F (29.7°C). Islamorada in September observes a slight diminution in temperature from daily highs, recording a low-temperature average of 81.7°F (27.6°C).Heat index
The heat index for September is calculated to be a tropical 93.2°F (34°C). Adopt extra preventive measures, the occurrence of heat cramps and heat exhaustion is likely. Heatstroke may follow extended activity.Note that heat index values are valued for light wind and location in the shade. In the presence of direct sunshine, the heat index could be augmented by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', integrates the air's temperature and its humidity to showcase the felt temperature by people. This effect is personal, influenced by the individual's physical activity and heat sensitivity, shaped by factors including wind, attire, and metabolic variations. When directly under the sun, the weather's impact can intensify, possibly boosting the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for children. Typically, children face more danger than adults as they usually perspire less. Their larger skin surface relative to their small bodies and increased heat output from their activities enhance their risk.
Humidity
In September, the average relative humidity is 74%.Rainfall
In Islamorada, Florida, in September, it is raining for 22.9 days, with typically 4.25" (108mm) of accumulated precipitation. Throughout the year, there are 190.1 rainfall days, and 27.05" (687mm) of precipitation is accumulated.Ocean temperature
In September, the average ocean temperature is 85.5°F (29.7°C).Note: Water temperature ranging from 77°F (25°C) to 84.2°F (29°C) is recognized as warm and pleasant by all, making water activities comfortable and delightful for long durations.
Daylight
In September, the average length of the day is 12h and 17min.On the first day of September, sunrise is at 7:03 am and sunset at 7:40 pm. On the last day of the month, sunrise is at 7:14 am and sunset at 7:10 pm EDT.
Sunshine
In September, the average sunshine is 9h.UV index
April through October, with an average maximum UV index of 7, are months with the highest UV index. A UV Index estimate of 6 to 7 represents a high health hazard from unprotected exposure to Sun's UV rays for the average person.Note: The daily high UV index of 7 during September translates into the following recommendations:
Implement precautions and maintain sun safety methods. Avoidance of sunburn is demanded. During the period from 10 a.m. to 4 p.m., UV radiation is highest. Try to avoid direct sunlight during these hours. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense. Caution! The mirror effect of sand and water ups the UV radiation strength.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is it hot during September?
What is the average humidity in September in Islamorada?
How many days does it rain in September?
What is the water temperature in September?
What is the average length of the day in September?
When are sunrise and sunset in September?
How many hours of sunshine does Islamorada have in September?
What is the month with the highest UV index?
What is the UV index reading in September?
Average temperature in September
Islamorada, FL
- Average high temperature in September: 84.6°F
The warmest month (with the highest average high temperature) is August (85.5°F).
The month with the lowest average high temperature is January (72.7°F).
- Average low temperature in September: 81.7°F
The month with the highest average low temperature is August (82.9°F).
The coldest month (with the lowest average low temperature) is January (66.9°F).
Average pressure in September
Islamorada, FL
- Average pressure in September: 29.94"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The months with the lowest atmospheric pressure are September and October (29.94"Hg).
Average wind speed in September
Islamorada, FL
- Average wind speed in September: 9.4mph
The windiest month (with the highest average wind speed) is January (12.9mph).
The calmest month (with the lowest average wind speed) is July (8.9mph).
Average humidity in September
Islamorada, FL
- Average humidity in September: 74%
The months with the highest relative humidity are February, June and December (76%).
The month with the lowest relative humidity is March (73%).
Average rainfall in September
Islamorada, FL
- Average rainfall in September: 4.25"
The wettest month (with the highest rainfall) is August (4.33").
The driest month (with the least rainfall) is March (0.59").
Average rainfall days in September
Islamorada, FL
- Average rainfall days in September: 22.9 days
The month with the highest number of rainy days is September (22.9 days).
The month with the least rainy days is February (9.7 days).
Average sea temperature in September
Islamorada, FL
- Average sea temperature in September: 85.4°F
The best month for swimming (with the highest average sea temperature) is August (86.6°F).
The coldest months (with the lowest average sea temperature) are January and February (73.9°F).
Average daylight in September /
Average sunshine in September
Islamorada, FL
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 13h and 42min).
The month with the shortest days is December (Average daylight: 10h and 36min).
- Average sunshine in September: 9h and 0min
The month with the most sunshine is July (Average sunshine: 11h and 0min).
The month with the least sunshine is December (Average sunshine: 6h and 24min).
Average sunshine days in September
Islamorada, FL
- Average sunshine days in September: 5.2 days
The month with the most sunshine days is January (17.3 days).
The month with the least sunshine days is September (5.2 days).
Average UV index in September
Islamorada, FL
- Average UV index in September: 7
The months with the highest UV index are April, May, June, July, August, September and October (UV index 7).
The month with the lowest UV index is January (UV index 5).
Average cloud cover in September
Islamorada, FL
- Average cloud cover in September: 30
The month with the most cloud cover is October (Cloud cover 35).
The month with the least cloud cover is April (Cloud cover 26).
Average visibility in September
Islamorada, FL
- 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).
Islamorada, Florida, USA
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