September weather forecastHolmes Beach, FL
September
Weather in September
The first month of the autumn, September, is still a tropical month in Holmes Beach, Florida, with an average temperature fluctuating between 77.9°F (25.5°C) and 86.2°F (30.1°C).Temperature
The transition into September notes an average high-temperature of a still hot 86.2°F (30.1°C), revealing a mild distinction from the 87.4°F (30.8°C) in August. Holmes Beach registers an average low-temperature of 77.9°F (25.5°C) throughout September, a modest decrease from its daytime highs.Heat index
In September, the average heat index is estimated at a torrid 98.6°F (37°C). Undertake special precautions, the probability of heat exhaustion and heat cramps is high. Prolonged activity may provoke heatstroke.Thinking about the heat index, one should account for its values in shaded areas with gentle breezes. Heat index values may rise by up to 15 Fahrenheit (8 Celsius) degrees when exposed to direct sunlight.
Note: The heat index, also known as 'real feel' or 'apparent temperature', is a composite of temperature and humidity figures to convey how warm it feels. Physical activity, clothing, and metabolic variations are additional factors that impact an individual's perception of temperature. Take note that direct exposure to the sun can increase the felt temperature, possibly adding 15 Fahrenheit (8 Celsius) degrees to the heat index. Heat index values are particularly meaningful 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.
Perspiration, which is the evaporation of sweat, is a primary way the human body manages and dispels excessive warmth. Higher relative humidity impedes evaporation, thus reducing heat dispersion from the body, culminating in a sensation of overheating. When body temperature rises due to excess heat gain beyond its removal capability, one might experience heat-related disorders.
Humidity
In Holmes Beach, the average relative humidity in September is 75%.Rainfall
In Holmes Beach, in September, during 21.5 rainfall days, 3.43" (87mm) of precipitation is typically accumulated. Throughout the year, there are 166.4 rainfall days, and 26.38" (670mm) of precipitation is accumulated.Ocean temperature
In Holmes Beach, in September, the average water temperature is 84.7°F (29.3°C).Note: Surface water temperatures ranging from 77°F (25°C) to 84.2°F (29°C) are seen as ideal and highly pleasant for extended enjoyment in all water activities.
Daylight
The average length of the day in September is 12h and 19min.On the first day of the month, sunrise is at 7:10 am and sunset at 7:51 pm. On the last day of September, in Holmes Beach, sunrise is at 7:23 am and sunset at 7:17 pm EDT.
Sunshine
In September, the average sunshine is 9.1h.UV index
The months with the highest UV index are May through September, with an average maximum UV index of 7. A UV Index of 6 to 7 symbolizes a high health hazard from unprotected exposure to Sun's UV rays for the average person.Note: The maximum UV index of 7 during September leads to these instructions:
Inhibit overexposure. Warding off sun damage is of utmost importance. UV radiation from the Sun is most intense between 10 a.m. and 4 p.m. Try to avoid direct sunlight during this period. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Be attentive! The UV exposure is heightened with reflections from sand and water.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Holmes Beach, FL
- Average high temperature in September: 86.2°F
The warmest month (with the highest average high temperature) is August (87.4°F).
The month with the lowest average high temperature is January (66.9°F).
- Average low temperature in September: 77.9°F
The month with the highest average low temperature is August (80.4°F).
The coldest month (with the lowest average low temperature) is January (56.8°F).
Average pressure in September
Holmes Beach, FL
- Average pressure in September: 29.96"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is September (29.96"Hg).
Average wind speed in September
Holmes Beach, FL
- Average wind speed in September: 8.2mph
The windiest month (with the highest average wind speed) is November (10.7mph).
The calmest month (with the lowest average wind speed) is July (7.1mph).
Average humidity in September
Holmes Beach, FL
- Average humidity in September: 75%
The month with the highest relative humidity is December (77%).
The month with the lowest relative humidity is October (73%).
Average rainfall in September
Holmes Beach, FL
- Average rainfall in September: 3.43"
The wettest month (with the highest rainfall) is July (4.88").
The driest month (with the least rainfall) is November (0.71").
Average rainfall days in September
Holmes Beach, FL
- Average rainfall days in September: 21.5 days
The months with the highest number of rainy days are July and August (24.6 days).
The month with the least rainy days is January (7.3 days).
Average sea temperature in September
Holmes Beach, 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
Holmes Beach, FL
- Average daylight in September: 12h and 18min
The month with the longest days is June (Average daylight: 13h and 54min).
The month with the shortest days is December (Average daylight: 10h and 24min).
- Average sunshine in September: 9h and 6min
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
Holmes Beach, FL
- Average sunshine days in September: 6 days
The month with the most sunshine days is January (22.6 days).
The months with the least sunshine days are July and August (4.8 days).
Average UV index in September
Holmes Beach, 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
Holmes Beach, FL
- Average cloud cover in September: 27
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 21).
Average visibility in September
Holmes Beach, 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).





