September weather forecast
Rio, FL

September, the first month of the autumn in Rio, is also a moderately hot month, with an average temperature varying between 78.3°F (25.7°C) and 85.3°F (29.6°C).

Temperature

The advent of September brings an average high-temperature of a warm 85.3°F (29.6°C), almost identical to the preceding month. Rio, during the nights of September, averages a temperature close to its daytime high, at a still moderately hot 78.3°F (25.7°C).

Heat index

For most parts of September, the heat index is estimated at a sweltering 96.8°F (36°C). Adopt heightened preventive measures, heat exhaustion and heat cramps are probable. Persistent activity could lead to heatstroke.
One should be cognizant that the heat index values are tailored for shaded spots and mild winds. Heat index values may rise by up to 15 Fahrenheit (8 Celsius) degrees when exposed to direct sunlight.
Note: The heat index, also known as 'real feel' or 'feels like', melds the effects of warmth and moisture to generate a feeling of heat. Additional factors encompassing metabolic differences, the level of physical activity, and clothing can impact the individual's perception of temperature. Direct exposure to sun rays can potentially augment the heat sensation, elevating the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular significance for children. In general, children are more at risk than adults because they sweat less. Furthermore, the large skin surface compared to their small bodies and the high heat production due to their actions contribute to this vulnerability.
The human body normally cools itself by perspiration. Excessive warmth is eliminated from the body by evaporation of sweat. When the air holds a significant amount of moisture, the efficiency of the evaporation process is decreased, preventing the body from cooling down efficiently, leading to the sensation of overheating. As the body gains more heat than it can dissipate, there's a risk of increasing temperatures and resultant overheating.

Humidity

In Rio, the average relative humidity in September is 77%.

Rainfall

In Rio, in September, during 22.6 rainfall days, 1.5" (38mm) of precipitation is typically accumulated. Throughout the year, there are 168.1 rainfall days, and 14.09" (358mm) of precipitation is accumulated.

Daylight

In Rio, 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 7:40 pm. On the last day of September, sunrise is at 7:13 am and sunset at 7:07 pm EDT.

Sunshine

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 of 6 to 7 symbolizes a high health hazard from exposure to the Sun's UV radiation for ordinary individuals.
Note: The daily high UV index of 7 in September translates into this advice:
Take precautions against overexposure. Fair-skinned people may get burned in less than 20 minutes. Avoid direct Sun exposure and stay in the shade between 10 a.m. and 4 p.m., a time when UV radiation is most intense, noting that not all shade structures offer full protection. Fend off the sun's harsh rays with appropriate clothing, a wide-brim hat, and UV-protective sunglasses.