September weather forecast
Manhattan, FL

September, the first month of the autumn in Manhattan, is still a tropical month, with an average temperature ranging between max 88.3°F (31.3°C) and min 74.8°F (23.8°C).

Temperature

August's transformation into September witnesses an average high-temperature of a still hot 88.3°F (31.3°C), noting a minor change from the preceding month. Throughout September, Manhattan records an average temperature of 74.8°F (23.8°C) at night.

Heat index

For September, the heat index is evaluated at a blisteringly hot 105.8°F (41°C). Undertake special precautions, the probability of heat exhaustion and heat cramps is high. Prolonged activity may provoke heatstroke.
Understanding the heat index involves considering values for shaded locales with light wind. 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 'real feel', is a single figure representing how weather conditions feel when combining temperature and humidity. The influence of weather can be personal, changing with an individual's body mass, height, and level of physical exertion. Under direct sun rays, the felt temperature might be heightened, with the heat index increasing by 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical for babies and toddlers. Young ones are generally more prone to risk than adults due to their reduced ability to sweat. Their large skin surface area relative to their diminutive bodies and elevated heat production from their activities further enhance this risk.
The innate cooling system of the human body revolves around perspiration, with the evaporation of sweat being central to this process. An upsurge in relative humidity affects normal body cooling mechanisms by slowing evaporation, hence reducing the rate at which the body cools and intensifying the perception 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

September is the most humid month, with an average relative humidity of 77%.

Rainfall

In Manhattan, Florida, in September, during 20.1 rainfall days, 1.5" (38mm) of precipitation is typically accumulated. Throughout the year, there are 159.5 rainfall days, and 15.16" (385mm) of precipitation is accumulated.

Daylight

The average length of the day in September is 12h and 19min.
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 7:21 am and sunset at 7:16 pm EDT.

Sunshine

In Manhattan, the average sunshine in September is 9h.

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 health risk from unprotected exposure to Sun's UV rays for ordinary individuals.
Note: A maximum UV index of 7 in September translates into the following recommendations:
Take precautions and adopt sun safety practices. Protection against sunburn is obliged. Avoid direct exposure to the Sun between 10 a.m. and 4 p.m., the peak period for UV radiation, noting that objects like parasols or canopies might not offer complete sun protection. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation.