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
A minor adjustment in Siesta Key's average high-temperature is noted with the start of September, touching a still tropical 86.9°F (30.5°C) from August's 88.5°F (31.4°C). In Siesta Key, the average low-temperature during the month of September is a warm 77.4°F (25.2°C).Heat index
The average heat index in September is evaluated at a torrid 100.4°F (38°C). Take more safety measures, heat exhaustion and heat cramps are potential outcomes. Persistent activity might lead to heatstroke.The heat index's values are generally associated with conditions in shade and light breezes. Heat index values can rise by 15 Fahrenheit (8 Celsius) degrees when in direct sunlight.
Note: The heat index, also known as 'real feel' or 'feels like', reflects the blend of air temperature and relative humidity to give a temperature impression. A person's impression of weather can be shaped by several aspects, among them metabolic variations, pregnancy, and levels of physical activity. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are primarily vital for children. Kids are usually more vulnerable than adults, given their lesser sweating ability. Along with their larger skin surface relative to their small stature and the excess heat due to their activity, their risk is amplified.
Perspiration is the body's default response to elevated temperatures, as it promotes the evaporation of sweat to achieve cooling. An increase in relative humidity retards evaporation, subsequently reducing the body's heat removal rate and leading to a sensation of being overly warm. The body is at risk of dehydration and related complications when it fails to shed excessive heat.
Humidity
In Siesta Key, the average relative humidity in September is 75%.Rainfall
In September, the rain falls for 23.5 days. Throughout September, 4.61" (117mm) of precipitation is accumulated. Throughout the year, there are 183.1 rainfall days, and 34.92" (887mm) of precipitation is accumulated.Ocean temperature
In September, the average ocean temperature is 84.7°F (29.3°C).Note: Ideal surface water temperatures for any water activity fall between 77°F (25°C) and 84.2°F (29°C), offering maximum enjoyment for lengthened periods.
Daylight
In September, the average length of the day is 12h and 19min.On the first day of the month, sunrise is at 7:09 am and sunset at 7:50 pm. On the last day of September, sunrise is at 7:22 am and sunset at 7:17 pm EDT.
Sunshine
In September, the average sunshine is 9h.UV index
The months with the highest UV index are May through September, with an average maximum UV index of 7. A UV Index estimate of 6 to 7 represents a high threat to health from exposure to the Sun's UV rays for average individuals.Note: The daily high UV index of 7 in September translates into this advice:
Implement preventive steps and embrace sun safety standards. Protection from skin and eye distress is compulsory. Be aware that the sun's UV radiation is strongest between 10 a.m. and 4 p.m. and try to reduce direct sun exposure during this period as much as possible. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense. Stay vigilant! UV rays get a boost in intensity due to sand and water reflections.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot is September?
What is the average humidity in September?
How much does it rain in September?
What is the ocean temperature in September?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How long on average sun shines in September?
What are the months with the highest UV index?
What is the UV index reading in September?
Average temperature in September
Siesta Key, FL
- Average high temperature in September: 86.9°F
The warmest month (with the highest average high temperature) is August (88.5°F).
The month with the lowest average high temperature is January (68.5°F).
- Average low temperature in September: 77.4°F
The month with the highest average low temperature is August (79.7°F).
The coldest month (with the lowest average low temperature) is January (56.1°F).
Average pressure in September
Siesta Key, FL
- Average pressure in September: 29.95"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is September (29.95"Hg).
Average wind speed in September
Siesta Key, FL
- Average wind speed in September: 7.2mph
The windiest month (with the highest average wind speed) is January (9.3mph).
The calmest month (with the lowest average wind speed) is July (6.4mph).
Average humidity in September
Siesta Key, FL
- Average humidity in September: 75%
The month with the highest relative humidity is December (76%).
The months with the lowest relative humidity are March, April and May (72%).
Average rainfall in September
Siesta Key, FL
- Average rainfall in September: 4.61"
The wettest month (with the highest rainfall) is August (6.42").
The driest months (with the least rainfall) are February and November (1.06").
Average rainfall days in September
Siesta Key, FL
- Average rainfall days in September: 23.5 days
The month with the highest number of rainy days is August (26.8 days).
The months with the least rainy days are January, February and November (8.3 days).
Average sea temperature in September
Siesta Key, FL
- Average sea temperature in September: 84.8°F
The best month for swimming (with the highest average sea temperature) is August (86.7°F).
The coldest month (with the lowest average sea temperature) is January (64.1°F).
Average daylight in September /
Average sunshine in September
Siesta Key, FL
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 13h and 48min).
The month with the shortest days is December (Average daylight: 10h and 30min).
- Average sunshine in September: 9h and 0min
The month with the most sunshine is May (Average sunshine: 11h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 30min).
Average sunshine days in September
Siesta Key, FL
- Average sunshine days in September: 4.5 days
The month with the most sunshine days is January (21.1 days).
The month with the least sunshine days is August (2.5 days).
Average UV index in September
Siesta Key, FL
- Average UV index in September: 7
The months with the highest UV index are May, June, July, August and September (UV index 7).
The month with the lowest UV index is January (UV index 4).
Average cloud cover in September
Siesta Key, FL
- Average cloud cover in September: 28
The months with the most cloud cover are January and December (Cloud cover 30).
The month with the least cloud cover is May (Cloud cover 22).
Average visibility in September
Siesta Key, 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).
Siesta Key, Florida, USA
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