September weather forecast
Captiva, FL

September marks the zenith of rainfall in Captiva with 1.02". The month sees a slight dip in temperature to 86.7°F, but the rainfall brings relief to the summer blaze. Concurrently, daylight and sunshine duration decelerate. As the summer begins to fade, the weather shifts, creating a captivating blend of warmth and rain.

Temperature

Captiva experiences a minor change to a still tropical 86.7°F in average high-temperature during September, closely reflecting August. Captiva's average low temperature, barely cooler than the daytime high, steadies at a warm 79°F during September.

Heat index

September's heat index is computed to be a fiery hot 98.6°F. Exercise more precautions, heat cramps and heat exhaustion are potential risks. Continuous activity could precipitate heatstroke.
Take note of the fact that heat index values are based on shaded circumstances with light airflows. The heat index may experience an enhancement of 15 Fahrenheit (8 Celsius) degrees under direct sunlight.
Note: The heat index, also known as 'feels like' or 'apparent temperature', combines both the air temperature and the humidity level to give a perceived human temperature. Factors such as metabolic variations, being pregnant, and physical activity can impact an individual's weather perception. Be mindful that being in direct sunlight might mean feeling hotter, with the heat index rising by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values remain especially vital for babies and toddlers. Young individuals usually face greater risks than adults as their sweat production is less. Also, their larger skin surface relative to their small bodies and the high heat generation due to their activity contributes to their vulnerability.
The human body cools itself through perspiration, as excessive warmth is removed from the body through sweat evaporation. Increased relative humidity interferes with body cooling by slowing the rate of evaporation, resulting in a slower body cooling rate and a heightened feeling of heat. As the body accumulates more heat than it can release, body temperature goes up, increasing the risk of heat-related health issues.

Humidity

The average relative humidity in September in Captiva, Florida, is 75%.

Rainfall

In Captiva, Florida, in September, during 19.5 rainfall days, 1.02" of precipitation is typically accumulated. Throughout the year, in Captiva, there are 122 rainfall days, and 8.98" of precipitation is accumulated.

Ocean temperature

In September, the average ocean temperature is 84.2°F.
Note: Engaging in swimming, diving, or other water activities is highly enjoyable in temperatures ranging from 77°F to 84.2°F, without any unpleasant sensations for prolonged durations.

Daylight

In Captiva, Florida, the average length of the day in September is 12h and 18min.
On the first day of September, sunrise is at 7:08 am and sunset at 7:49 pm. On the last day of the month, sunrise is at 7:20 am and sunset at 7:16 pm EDT.

Sunshine

In September, the average sunshine is 9.1h.

UV index

May through September, with an average maximum UV index of 7, are months with the highest UV index in Captiva. A UV Index reading of 6 to 7 represents a high threat to health from unsafe exposure to UV radiation for average individuals.
Note: The average daily UV index of 7 in September transforms into the following instructions:
Deflect overexposure. Sun protection is a necessity. Limit direct sun exposure especially between 10 a.m. and 4 p.m., when UV radiation is at its peak. However, keep in mind that shade structures may not provide full sun protection. To cut down UV radiation exposure by about half, sport a wide-brim hat. Stay aware! UV radiation is magnified when reflecting off sand and water.