September weather forecast
Sebastian, FL

The first month of the autumn, September, is still a warm month in Sebastian, Florida, with temperature in the range of an average high of 85.1°F (29.5°C) and an average low of 77.7°F (25.4°C).

Temperature

Sebastian, Florida, experiences a transition to a moderately hot 85.1°F (29.5°C) in average high-temperatures with the arrival of September, not greatly differing from August's 87.1°F (30.6°C). Sebastian welcomes an average low temperature of 77.7°F (25.4°C) in September, a gentle shift from the day's high.

Heat index

The heat index value during September is appraised at a torrid 96.8°F (36°C). Take more safety measures, heat exhaustion and heat cramps are potential outcomes. Persistent activity might lead to heatstroke.
Consider that heat index readings are for situations in the shade and light wind. Uninterrupted exposure to the sun may boost the heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'feels like', ties air temperature with relative humidity to produce the perceived temperature sensation. The impact of temperature is individual, as people's perception of weather may change based on their body mass, height, and physical activity. Direct sun exposure is noteworthy in its ability to escalate the felt temperature, potentially adding 15 Fahrenheit (8 Celsius) degrees to the heat index. Heat index values are quite important for babies and toddlers. Young individuals usually face more risks than adults due to their lower sweat production. Their large skin surface area relative to their tiny bodies and high heat production from their activities adds to their risk.
By perspiring, the human body can shed its excessive warmth since evaporated sweat cools it off. 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. Inadequate heat shedding in the face of rising body temperatures hints at potential dehydration risks.

Humidity

The average relative humidity in September in Sebastian is 78%.

Rainfall

In Sebastian, in September, during 23.5 rainfall days, 4.53" (115mm) of precipitation is typically accumulated. Throughout the year, in Sebastian, there are 205.2 rainfall days, and 38.31" (973mm) of precipitation is accumulated.

Daylight

In Sebastian, the average length of the day in September is 12h and 19min.
On the first day of the month, sunrise is at 7:00 am and sunset at 7:42 pm. On the last day of September, in Sebastian, sunrise is at 7:14 am and sunset at 7:08 pm EDT.

Sunshine

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

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 unsafe exposure to UV radiation for the average person.
Note: The UV index of 7 during September leads to these advisories:
Dodge overexposure. Fair-skinned people can get singed in less than 20 minutes. During the period from 10 a.m. to 4 p.m., UV radiation is highest. Try to avoid direct sunlight during these hours. On days when the sun blazes, arm yourself with sunglasses that block UVA and UVB radiation.