September weather forecast
Keysville, FL

The first month of the autumn, September, is still a hot month in Keysville, Florida, with an average temperature ranging between max 88.2°F (31.2°C) and min 73.6°F (23.1°C).

Temperature

Keysville marks the onset of September with an average high-temperature of a still hot 88.2°F (31.2°C), subtly divergent from August's 90°F (32.2°C). The temperature in Keysville dips to an average of 73.6°F (23.1°C) during September nights.

Heat index

The average heat index in September is estimated at an extremely hot 105.8°F (41°C). Undertake special precautions, the probability of heat exhaustion and heat cramps is high. Prolonged activity may provoke heatstroke.
Given the heat index, its values are aligned with shaded sites and gentle winds. When under direct sunshine, the heat index may be elevated by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'apparent temperature', is an aggregate value of air's warmth and moisture to show the human-felt temperature. The influence of weather is personal, with a diverse population experiencing it differently due to differences in body mass, stature, and degree of activity. Keep in mind that direct sunshine exposure can amplify the weather's effects, possibly increasing the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are of high significance for children. Youngsters often neglect the necessity for rest and hydration. Thirst is a sign of advancing dehydration - thus the importance of maintaining hydration, specifically during long-lasting physical activities.
The body's innate mechanism to counteract overheating is through perspiration, as it leverages the cooling effects of sweat evaporation. When relative humidity increases, the body's capacity to evaporate heat decreases, leading to a heightened sense of warmth. Rising body temperatures resulting from an imbalance in heat absorption can lead to potential thermal issues.

Humidity

August and September, with an average relative humidity of 79%, are the most humid months in Keysville.

Rainfall

In Keysville, in September, during 20.6 rainfall days, 3.98" (101mm) of precipitation is typically accumulated. Throughout the year, there are 189 rainfall days, and 36.54" (928mm) of precipitation is accumulated.

Daylight

In September, the average length of the day is 12h and 19min.
On the first day of September, sunrise is at 7:07 am and sunset at 7:48 pm. On the last day of the month, sunrise is at 7:21 am and sunset at 7:15 pm EDT.

Sunshine

In September, the average sunshine is 8.6h.

UV index

The months with the highest UV index are May through September, with an average maximum UV index of 7. A UV Index of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV rays for ordinary individuals.
Note: In September, a daily maximum UV index of 7 leads to the following instructions:
Beware of overexposure. Fair-skinned individuals risk burning in less than 20 minutes. From 10 a.m. to 4 p.m., when UV radiation is at its strongest, limit direct exposure to the Sun and note that shade structures may not provide full sun protection. In the presence of strong sunlight, it's crucial to wear sunglasses that ward off UVA and UVB rays.