September weather forecast
Slave Island, Sri Lanka

The first month of the autumn, September, is still a warm month in Slave Island, Sri Lanka, with an average temperature fluctuating between 24.9°C (76.8°F) and 29.1°C (84.4°F).

Temperature

The advent of September reveals an average high-temperature of a still moderately hot 29.1°C (84.4°F), showing minimal difference from the prior month. In Slave Island, the nighttime temperature shows a slight difference from the daytime high, averaging to a still warm 24.9°C (76.8°F) during September.

Heat index

For September, the heat index is appraised at a fiery hot 35°C (95°F). More safety actions are required, heat exhaustion and heat cramps are probable. Long-term activity may precipitate heatstroke.
Consider that heat index readings are for situations in the shade and light wind. Direct sunlight exposure may result in a rise of the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', gives a temperature feeling by integrating air temperature and humidity. One's perception of temperature is subjective, varying based on their activity and individual heat perception, influenced by factors like wind, clothing, and metabolic variations. With the sun shining directly, it's crucial to understand that it can increase the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for children. Kids are usually more vulnerable than adults, given their lesser sweating ability. Along with their larger skin surface relative to their small stature and the excess heat due to their activity, their risk is amplified.
Evaporating sweat, an outcome of perspiration, is key in assisting the human body to moderate its temperature. Increased relative humidity slows down evaporation, thereby decreasing the rate of heat removal from the body, culminating in a sensation of overheating. Heat disorders may be on the horizon when body temperatures rise from inadequate heat management.

Humidity

In Slave Island, Sri Lanka, the average relative humidity in September is 81%.

Rainfall

In September, the rain falls for 26.9 days. Throughout September, 206mm (8.11") of precipitation is accumulated. Throughout the year, in Slave Island, there are 289.4 rainfall days, and 2262mm (89.06") of precipitation is accumulated.

Daylight

In Slave Island, the average length of the day in September is 12h and 10min.
On the first day of September, sunrise is at 06:03 and sunset at 18:17. On the last day of the month, sunrise is at 05:58 and sunset at 18:02 +0530.

Sunshine

In Slave Island, Sri Lanka, the average sunshine in September is 7.4h.

UV index

The months with the highest UV index in Slave Island, Sri Lanka, are January through April, July, September, November and December, with an average maximum UV index of 7. A UV Index estimate of 6 to 7 represents a high threat to health from exposure to the Sun's UV rays for ordinary individuals.
Note: The UV index of 7 during September translates into the following guidance:
Continue precautions and advocate sun safety advice. Deterrence of sunburn is indispensable. Stay in the shade and limit direct Sun exposure from 10 a.m. to 4 p.m., a time when UV radiation is particularly strong. Remember, however, that shade structures may not provide complete protection. A hat with a broad brim is indispensable, filtering out up to half of UV rays.