September weather forecast
Hanwella, Sri Lanka

The first month of the autumn, September, is also a moderately hot month in Hanwella, Sri Lanka, with an average temperature varying between 24.9°C (76.8°F) and 29.1°C (84.4°F).

Temperature

The shift into September finds Hanwella at an average high-temperature of a still moderately hot 29.1°C (84.4°F), closely comparable to August's conditions. During September, Hanwella's nighttime temperatures demonstrate a subtle cooling from daytime highs, stabilizing at a still warm 24.9°C (76.8°F).

Heat index

For most parts of September, the heat index is calculated to be a sweltering 35°C (95°F). Adopt heightened preventive measures, heat exhaustion and heat cramps are probable. Persistent activity could lead to heatstroke.
The metrics for the heat index are tailored for both shady environments and light winds. Heat index values may be hiked up by 15 Fahrenheit (8 Celsius) degrees under direct sunshine.
Note: The heat index, also known as 'feels like' or 'real feel', ties air temperature with relative humidity to produce the perceived temperature sensation. Factors such as metabolic variations, being pregnant, and physical activity can impact an individual's weather perception. 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 are quite important for children. Children often overlook the need for breaks and fluid intake. Thirst is a late-stage sign of dehydration - hence, it is necessary to stay hydrated, especially during extended periods of physical activities.
Perspiration is the body's default response to elevated temperatures, as it promotes the evaporation of sweat to achieve cooling. Under conditions of high relative humidity, the rate of evaporation decreases. This results in the body retaining more heat than under conditions of dry air. Potential thermal conditions emerge as the body's heat gain outpaces its cooling mechanisms.

Humidity

In Hanwella, the average relative humidity in September is 81%.

Rainfall

In September, in Hanwella, the rain falls for 26.9 days. Throughout September, 206mm (8.11") of precipitation is accumulated. In Hanwella, during the entire year, the rain falls for 289.4 days and collects up to 2262mm (89.06") of precipitation.

Daylight

In Hanwella, Sri Lanka, the average length of the day in September is 12h and 10min.
On the first day of the month, sunrise is at 06:02 and sunset at 18:16. On the last day of September, in Hanwella, sunrise is at 05:57 and sunset at 18:01 +0530.

Sunshine

The average sunshine in September is 7.4h.

UV index

The months with the highest UV index are January through April, July, September, November and December, with an average maximum UV index of 7. A UV Index reading of 6 to 7 represents a high health risk from exposure to the Sun's UV rays for the ordinary person.
Note: The maximum daily UV index of 7 during September translates into the following directions:
Conform to measures and uphold sun safety traditions. Warding off skin and eye harm is necessary. Stay out of direct sunlight and seek shade between 10 a.m. and 4 p.m., when UV radiation is strongest, but remember that shade devices may not offer full sun protection. Tightly woven clothing, when worn loosely, shields effectively against the Sun.