September weather forecastSummerland Key, FL
September
Weather in September
The first month of the autumn, September, is still a warm month in Summerland Key, Florida, with an average temperature fluctuating between 84.4°F (29.1°C) and 82.2°F (27.9°C).Temperature
With the onset of September, Summerland Key's average high-temperature clocks in at a still moderately hot 84.4°F (29.1°C), showing a minor fluctuation from the previous month. A mean low-temperature of 82.2°F (27.9°C) is a distinguishing feature of September, indicating a slight dip from daytime highs.Heat index
September's average heat index is calculated to be a tropical 93.2°F (34°C). Incorporate extra safety measures to avoid heat exhaustion and heat cramps. Continuous activity could provoke heatstroke.Heat index evaluations are typically in the context of light winds and shaded environments. Heat index values may surge by up to 15 Fahrenheit (8 Celsius) degrees in the presence of direct sunlight.
Note: The heat index, also known as 'real feel' or 'apparent temperature', stands as a testimony to how temperature and humidity combine to impact our sense of warmth. One's weather perception can be influenced by a range of factors including metabolic differences, being pregnant, and their level of physical activity. It is important to note that direct sunlight can intensify the weather impact, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to babies and toddlers. 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
The months with the lowest humidity are July through September, with an average relative humidity of 74%.Rainfall
The month with the most rainfall is September, when the rain falls for 20.8 days and typically aggregates up to 3.54" (90mm) of precipitation.Daylight
In Summerland Key, the average length of the day in September is 12h and 17min.On the first day of the month, sunrise is at 7:07 am and sunset at 7:43 pm. On the last day of September, sunrise is at 7:17 am and sunset at 7:13 pm EDT.
Sunshine
The average sunshine in September is 9h.UV index
The months with the highest UV index in Summerland Key are April through October, with an average maximum UV index of 7. A UV Index of 6 to 7 symbolizes a high health vulnerability from exposure to the Sun's UV rays for ordinary individuals.Note: The daily high UV index of 7 during September translates into the following recommendations:
Apply measures and align with sun safety principles. Safeguarding against skin and eye injury is pivotal. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Summerland Key, FL
- Average high temperature in September: 84.4°F
The warmest month (with the highest average high temperature) is August (85.3°F).
The month with the lowest average high temperature is January (72.7°F).
- Average low temperature in September: 82.2°F
The month with the highest average low temperature is August (83.1°F).
The coldest month (with the lowest average low temperature) is January (68.5°F).
Average pressure in September
Summerland Key, FL
- Average pressure in September: 29.93"Hg
The month with the highest atmospheric pressure is January (30.09"Hg).
The months with the lowest atmospheric pressure are September and October (29.93"Hg).
Average wind speed in September
Summerland Key, FL
- Average wind speed in September: 10.1mph
The windiest month (with the highest average wind speed) is November (14.4mph).
The calmest month (with the lowest average wind speed) is July (9.4mph).
Average humidity in September
Summerland Key, FL
- Average humidity in September: 74%
The month with the highest relative humidity is February (78%).
The months with the lowest relative humidity are July, August and September (74%).
Average rainfall in September
Summerland Key, FL
- Average rainfall in September: 3.54"
The wettest month (with the highest rainfall) is September (3.54").
The driest month (with the least rainfall) is March (0.43").
Average rainfall days in September
Summerland Key, FL
- Average rainfall days in September: 20.8 days
The month with the highest number of rainy days is September (20.8 days).
The month with the least rainy days is March (9.4 days).
Average daylight in September /
Average sunshine in September
Summerland Key, FL
- Average daylight in September: 12h and 18min
The month with the longest days is June (Average daylight: 13h and 36min).
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 6min).
The month with the least sunshine is December (Average sunshine: 6h and 30min).
Average sunshine days in September
Summerland Key, FL
- Average sunshine days in September: 6.2 days
The month with the most sunshine days is March (19.6 days).
The month with the least sunshine days is September (6.2 days).
Average UV index in September
Summerland Key, 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
Summerland Key, FL
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 34).
The month with the least cloud cover is April (Cloud cover 23).
Average visibility in September
Summerland 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).





