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 introduction of September sees an average high-temperature of a still tropical 86.9°F, hardly deviating from August. Throughout September, Siesta Key's nights cool down to an average of 77.4°F.Heat index
September's heat index is computed to be a torrid 100.4°F. Special measures are necessary to avoid heat cramps and heat exhaustion. Persistent activity could result in heatstroke.It is worth noting that heat index values are gauged for conditions in the shade and light breezes. Direct exposure to sunlight could raise the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'feels like', reflects the feeling of heat when considering both air temperature and humidity. This effect tends to be personal, with the weather perception differing among individuals due to variations in body mass, height, and exertion. With direct sunlight, be aware that it might enhance the heat sensation, raising the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular importance for children. Young individuals usually face greater risks than adults as their sweat production is less. Also, their larger skin surface relative to their small bodies and the high heat generation due to their activity contributes to their vulnerability.
The physiological way the human body responds to excessive heat is by inducing perspiration, using sweat evaporation as a cooling mechanism. Relative humidity in excess curtails evaporation, therefore reducing heat dissipation from the body, leading to feelings of excess heat. When the heat gained surpasses the body's cooling capacity, temperatures rise, signaling potential health concerns.
Humidity
In September, the average relative humidity is 75%.Rainfall
In September, the rain falls for 23.5 days. Throughout September, 4.61" of precipitation is accumulated. In Siesta Key, during the entire year, the rain falls for 183.1 days and collects up to 34.92" of precipitation.Ocean temperature
In Siesta Key, the average seawater temperature in September is 84.7°F.Note: For any water activity, having surface water temperatures from 77°F to 84.2°F is considered outstanding and highly delightful for lengthened periods.
Daylight
In September, the average length of the day in Siesta Key is 12h and 19min.On the first day of September, sunrise is at 7:09 am and sunset at 7:51 pm. On the last day of the month, sunrise is at 7:22 am and sunset at 7:18 pm EDT.
Sunshine
The average sunshine in September is 9h.UV index
May through September, with an average maximum UV index of 7, are months with the highest UV index. A UV Index value of 6 to 7 symbolizes a high threat to health from unsafe exposure to UV radiation for the ordinary person.Note: The maximum daily UV index of 7 during September translates into the following directions:
Apply measures and align with sun safety principles. Safeguarding against skin and eye injury is pivotal. From 10 a.m. to 4 p.m., when UV radiation is at its strongest, limit direct exposure to the Sun and note that shade structures may not provide full sun protection. On days when the sun blazes, arm yourself with sunglasses that block UVA and UVB radiation. Warning! Sand and water reflections boost the intensity of UV exposure.
FAQ
Is it hot in Siesta Key during September?
What is the average humidity in September in Siesta Key?
How much does it rain in Siesta Key in September?
What is the water temperature in September in Siesta Key?
How many hours of daylight does Siesta Key have in September?
What time are sunrise and sunset in September in Siesta Key?
How long on average sun shines in September in Siesta Key?
When is the highest UV index in Siesta Key?
What is the UV index reading in September in Siesta Key?
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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