September weather forecast
Fort Myers, FL

September witnesses the onset of fall, with a slight decrease in temperature, offering a respite from the summer. The rainfall levels retreat from their August high, indicating a slow transition toward drier months. The daylight hours begin reducing, signaling the end of long summer days. However, the city remains lively due to the pleasant sea temperature, the brightness of sunny hours, and vibrant surroundings. The humidity remains fairly constant, fostering a relatively comfortable environment.

Temperature

The arrival of September is marked by an average high-temperature of a still hot 87.6°F (30.9°C), bearing a close resemblance to August. During September, the average low-temperature is a warm 76.6°F (24.8°C).

Heat index

September's heat index is calculated to be a very hot 102.2°F (39°C). Implement more safety precautions, heat cramps and heat exhaustion may happen. Persistent activity could induce heatstroke.
When referencing the heat index, its values are suitable for shady environments and light breezes. The heat index has the potential to rise by 15 Fahrenheit (8 Celsius) degrees with direct sunshine exposure.
Note: The heat index, also known as 'feels like' or 'real feel', is found by incorporating humidity levels into the air temperature measurement. The impact of weather is personal, differing among a variety of people based on differences in body mass, height, and the level of physical exertion. It is noteworthy to mention that direct sunlight exposure can augment the felt temperature, leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are primarily vital for children. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.
The human body cools itself through perspiration, as excessive warmth is removed from the body through sweat evaporation. Elevated relative humidity disrupts typical body cooling by reducing the evaporation rate, consequently decreasing the body's cooling rate and enhancing the feeling of heat. Heat-related disorders may develop if heat gain in the body overshadows its cooling capacity, leading to elevated temperatures.

Humidity

September and December, with an average relative humidity of 76%, are the most humid months.

Rainfall

In Fort Myers, during September, the rain falls for 20.9 days and regularly aggregates up to 2.95" (75mm) of precipitation. In Fort Myers, during the entire year, the rain falls for 159.2 days and collects up to 23.54" (598mm) of precipitation.

Ocean temperature

In September, the average ocean temperature is 84.2°F (29°C).
Note: Swimming, diving, and other activities in water temperatures between 77°F (25°C) and 84.2°F (29°C) are thought to be quite enjoyable and satisfying for extended periods, with no discomfort.

Daylight

The average length of the day in September is 12h and 18min.
On the first day of the month, sunrise is at 7:07 am and sunset at 7:47 pm. On the last day of September, sunrise is at 7:19 am and sunset at 7:14 pm EDT.

Sunshine

In Fort Myers, the average sunshine in September is 9.2h.

UV index

The months with the highest UV index are May through September, with an average maximum UV index of 7. 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: In September, the average maximum UV index of 7 translates into the following recommendations:
Adopt measures and apply sun safety strategies. Shielding from skin and eye damage is necessary. During the period from 10 a.m. to 4 p.m., UV radiation is highest. Try to avoid direct sunlight during these hours. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized. Be wary! Reflections from sand and water make UV radiation more intense.