September weather forecast
Myrtle Island, FL

September, the first month of the autumn in Myrtle Island, is still a hot month, with an average temperature ranging between max 88.7°F (31.5°C) and min 73.4°F (23°C).

Temperature

September's advent denotes a minor fluctuation in the average high-temperature to a still hot 88.7°F (31.5°C) from August's 92.3°F (33.5°C). In September, the temperature drops to an average of 73.4°F (23°C) at night.

Heat index

The average heat index in September is estimated at a blistering 105.8°F (41°C). Preventive measures are required to mitigate the risk of heat cramps and heat exhaustion. Continuous activity may precipitate heatstroke.
Evaluating the heat index requires understanding its values in the shade and with gentle winds. 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 the outcome of merging air's temperature and its humidity metrics. Additional elements encompassing metabolic differences, the degree of physical activity, and attire can impact the individual's perception of temperature. Exposure to direct sun rays can influence the heat you feel, pushing the heat index up by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to babies and toddlers. Young kids are often more at risk than adults as they tend to perspire less. Besides, their skin surface is larger relative to their small bodies, and their increased heat output from their active lifestyle compounds their risk.
In response to overheating, the human body perspires to cool down, mainly through the evaporation of sweat. Increased relative humidity slows down evaporation, thereby decreasing the rate of heat removal from the body, culminating in a sensation of overheating. Accumulating heat beyond the body's cooling measures leads to rising temperatures and potential ailments.

Humidity

The months with the highest humidity are July through September, with an average relative humidity of 77%.

Rainfall

In September, the rain falls for 15.7 days. Throughout September, 1.85" (47mm) of precipitation is accumulated. Throughout the year, there are 151.1 rainfall days, and 17.99" (457mm) of precipitation is accumulated.

Daylight

In September, the average length of the day is 12h and 20min.
On the first day of September, sunrise is at 7:03 am and sunset at 7:47 pm. On the last day of the month, sunrise is at 7:18 am and sunset at 7:12 pm EDT.

Sunshine

The average sunshine in September is 8.1h.

UV index

In September, the average daily maximum UV index is 6. A UV Index value of 6 to 7 symbolizes a high health vulnerability from unsafe exposure to UV radiation for the average person.
Note: In September, the maximum UV index of 6 transforms into these recommendations:
Escape overexposure. People with light skin may incur burns in fewer than 20 minutes. Avoid direct Sun exposure from 10 a.m. to 4 p.m., a period when UV radiation is most intense, and remember that not all shade structures provide full protection. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage.