September weather forecastSaint James City, FL
September
Weather in September
September, the first month of the autumn in Saint James City, is still a tropical month, with an average temperature varying between 86.7°F (30.4°C) and 79°F (26.1°C).Temperature
September's commencement is accompanied by an average high-temperature of a still hot 86.7°F (30.4°C), diverging marginally from August's 88°F (31.1°C). Saint James City's nighttime temperature in September shows a minor descent, with a steady average of 79°F (26.1°C).Heat index
During September, the heat index is calculated to be a very hot 98.6°F (37°C). Extra precautions are necessary, heat cramps and heat exhaustion are plausible outcomes. Extended activity could lead to heatstroke.It is worth noting that heat index values are gauged for conditions in the shade and light breezes. Direct sunlight might cause an increase of up to 15 Fahrenheit (8 Celsius) degrees in the heat index.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', ties air temperature with relative humidity to produce the perceived temperature sensation. Additional elements including metabolic differences, the level of physical activity, and attire have a role in shaping the individual's temperature perception. One must note that being under the direct sun can escalate the heat's effects, with the heat index possibly rising by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to children. Kids frequently fail to realize the necessity for resting and hydrating. Thirst is an advanced indication of dehydration - hence, maintaining hydration, especially during extended physical activities, becomes essential.
Sweat evaporation, driven by perspiration, is the method the human body uses to rid itself of excessive warmth. In situations of high air temperature combined with high humidity (significant heat index), the body's ability to perspire is reduced, heightening the sense of warmth. When the body is unable to balance heat gain, its temperature elevates, which may induce thermal illnesses.
Humidity
The average relative humidity in September in Saint James City is 75%.Rainfall
In Saint James City, during September, the rain falls for 19.5 days and regularly aggregates up to 1.02" (26mm) of precipitation. In Saint James City, during the entire year, the rain falls for 122 days and collects up to 8.98" (228mm) of precipitation.Ocean temperature
In Saint James City, in September, the average water temperature is 85.3°F (29.6°C).Note: For swimming, diving, and similar activities, the water temperatures between 77°F (25°C) and 84.2°F (29°C) are considered delightful, allowing for extended periods of enjoyment without discomfort.
Daylight
The average length of the day in September in Saint James City, Florida, is 12h and 18min.On the first day of September in Saint James City, sunrise is at 7:08 am and sunset at 7:47 pm. On the last day of the month, sunrise is at 7:20 am and sunset at 7:15 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 risk from exposure to the Sun's UV rays for average individuals.Note: A typical high UV index of 7 in September suggests the following recommendations:
Persist in precautions and follow sun safety policies. Keeping sunburn at bay is imperative. Stay in the shade and limit direct Sun exposure from 10 a.m. to 4 p.m., a time when UV radiation is particularly strong. Remember, however, that shade structures may not provide complete protection. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation. 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
Average temperature in September
Saint James City, FL
- Average high temperature in September: 86.7°F
The warmest month (with the highest average high temperature) is August (88°F).
The month with the lowest average high temperature is January (70°F).
- Average low temperature in September: 79°F
The month with the highest average low temperature is August (81°F).
The coldest month (with the lowest average low temperature) is January (58.8°F).
Average pressure in September
Saint James City, FL
- Average pressure in September: 29.95"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is September (29.95"Hg).
Average wind speed in September
Saint James City, FL
- Average wind speed in September: 7.9mph
The windiest months (with the highest average wind speed) are October and November (9.9mph).
The calmest month (with the lowest average wind speed) is July (6.9mph).
Average humidity in September
Saint James City, FL
- Average humidity in September: 75%
The month with the highest relative humidity is December (77%).
The month with the lowest relative humidity is March (72%).
Average rainfall in September
Saint James City, FL
- Average rainfall in September: 1.02"
The wettest month (with the highest rainfall) is August (1.93").
The driest month (with the least rainfall) is March (0.16").
Average rainfall days in September
Saint James City, FL
- Average rainfall days in September: 19.5 days
The month with the highest number of rainy days is September (19.5 days).
The month with the least rainy days is February (4.1 days).
Average sea temperature in September
Saint James City, FL
- Average sea temperature in September: 85.4°F
The best month for swimming (with the highest average sea temperature) is August (87.1°F).
The coldest month (with the lowest average sea temperature) is January (65.3°F).
Average daylight in September /
Average sunshine in September
Saint James City, FL
- Average daylight in September: 12h and 18min
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 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 42min).
Average sunshine days in September
Saint James City, FL
- Average sunshine days in September: 7.2 days
The month with the most sunshine days is January (25.1 days).
The month with the least sunshine days is September (7.2 days).
Average UV index in September
Saint James City, 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 months with the lowest UV index are January and February (UV index 5).
Average cloud cover in September
Saint James City, FL
- Average cloud cover in September: 28
The month with the most cloud cover is January (Cloud cover 29).
The months with the least cloud cover are March and May (Cloud cover 23).
Average visibility in September
Saint James City, 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).





