September weather forecast
Treasure Island, FL

September brings a slight relief from the summer highs, as temperatures fall between 77.9°F (25.5°C) and 86.5°F (30.3°C). The skies are less sunny compared to August, indicating the gradual transition towards the fall season. Rainfall also witnesses a decrease, with about 17.5 days of precipitation in the month, giving way to clearer skies. The sea cools down gracefully, still maintaining an appealing temperature. A hike in the wind speed to about 7.9mph (12.7km/h) makes evenings in Treasure Island quite pleasant.

Temperature

In September, Treasure Island's weather conditions record an average high-temperature of a still hot 86.5°F (30.3°C), demonstrating little divergence from the preceding month. Treasure Island's nocturnal average in September closely mirrors its daytime temperatures, settling at a warm 77.9°F (25.5°C).

Heat index

The heat index in September is calculated to be a torrid 98.6°F (37°C). Heightened precautions are necessary, heat cramps and heat exhaustion are potential risks. Continuous activity could lead to heatstroke.
It is noted that heat index values are ascertained for locations in the shade and with gentle breezes. Exposure to the sun directly might heighten the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', is derived by integrating air temperature with the existing relative humidity to express the perceived warmth. An individual's temperature experience can be influenced by extra factors, including metabolic differences, activity levels, and clothing. 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 especially crucial for babies and toddlers. Children usually face more risks than adults as their ability to sweat is less. Additionally, their larger skin surface in relation to their petite bodies and higher heat output due to their activities increases their vulnerability.
Perspiring is how the human body naturally cools down, as sweat's evaporation takes away excess heat. When the level of relative humidity is elevated, evaporation diminishes, causing more warmth to be retained in the body than in dry air. When body heat isn't effectively managed, risks of dehydration and overheating amplify.

Humidity

In September, the average relative humidity is 74%.

Rainfall

In Treasure Island, in September, during 17.5 rainfall days, 1.02" (26mm) of precipitation is typically accumulated. In Treasure Island, during the entire year, the rain falls for 122.3 days and collects up to 9.45" (240mm) of precipitation.

Ocean temperature

In Treasure Island, Florida, the average seawater temperature in September is 84.7°F (29.3°C).
Note: Water surface temperatures from 77°F (25°C) to 84.2°F (29°C) are considered optimal and extremely delightful for long-lasting pleasure in any water activity.

Daylight

In Treasure Island, the average length of the day in September is 12h and 19min.
On the first day of September, sunrise is at 7:10 am and sunset at 7:51 pm. On the last day of the month, sunrise is at 7:23 am and sunset at 7:17 pm EDT.

Sunshine

In Treasure Island, the average sunshine in September is 9.2h.

UV index

May through September, with an average maximum UV index of 7, are months with the highest UV index. A UV Index value of 6 to 7 symbolizes a high health vulnerability from exposure to the Sun's UV radiation for the average person.
Note: An average maximum UV index of 7 in September leads to these recommendations:
Inhibit overexposure. Warding off sun damage is of utmost importance. Stay in the shade and avoid direct Sun exposure from 10 a.m. to 4 p.m., a period when UV radiation is particularly strong, noting that parasols or canopies may not offer total sun protection. Always opt for UVA and UVB-resistant sunglasses on radiant days. Note! Reflective surfaces like sand and water heighten the UV radiation levels.