September weather forecast and climate
Dehiwala, Sri Lanka

The first month of the autumn, September, is also a hot month in Dehiwala, Sri Lanka, with average temperature ranging between min 25°C (77°F) and max 30°C (86°F).

Temperature

June through December, with an average high-temperature of 30°C (86°F), are the coldest months.

Rainfall

In Dehiwala, during September, the rain falls for 14 days and regularly aggregates up to 236mm (9.3") of precipitation. Throughout the year, in Dehiwala, Sri Lanka, there are 139 rainfall days, and 2402mm (94.6") of precipitation is accumulated.

Sea temperature

In Dehiwala, in September, the average water temperature is 27.8°C (82°F). For any water activity, surface water temperatures between 25°C (77°F) and 29°C (84.2°F) are considered as excellent and extremely pleasant for lengthened periods.

Daylight

In September, the average length of the day is 12.2h.

Sunshine

Months with the least sunshine in Dehiwala are May through October, with an average of 6h of sunshine.

UV index

Months with the highest UV index are February through October, with an average maximum UV index of 12. A UV Index reading of 11, and higher, represents an extreme threat to health from the exposure to the Sun's UV radiation for ordinary individuals.
The daily maximum UV index of 12 in September interpret into the following advice:
Take all necessary precautions, as unprotected skin can burn in minutes. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. A broad-spectrum sunscreen of SPF 30+ should be liberally applied and re-applied every two hours, and immediately after an outdoor workout or a swim. Beware! The reflection of water and sand dramatically increases exposure to the UV rays.

What are the coldest months in Dehiwala?

The coldest months are June through December, with an average high-temperature of 30°C (86°F).

What is the temperature in September in Dehiwala?

In September, in Dehiwala, Sri Lanka, the average high-temperature is 30°C (86°F), and the average low-temperature is 25°C (77°F).

How many days does it rain in September in Dehiwala?

In Dehiwala, Sri Lanka, during September, the rain falls for 14 days and regularly aggregates up to 236mm (9.3") of precipitation.

What is the water temperature in September in Dehiwala?

In Dehiwala, in September, the average water temperature is 27.8°C (82°F). For swimming, diving, and other water activities, temperatures between 25°C (77°F) and 29°C (84.2°F) are perceived as very enjoyable and pleasurable for prolonged periods without feeling uncomfortable.

How many hours of daylight does Dehiwala have in September?

In Dehiwala, Sri Lanka, the average length of the day in September is 12.2h.

What is the month with the least sunshine in Dehiwala?

May through October, with an average of 6h of sunshine, are months with the least sunshine in Dehiwala, Sri Lanka.

How many hours of sunshine does Dehiwala have in September?

The average sunshine in September in Dehiwala, Sri Lanka, is 6h.

What is the month with the highest UV index in Dehiwala?

February through October, with an average maximum UV index of 12, are months with the highest UV index in Dehiwala.

What is the UV index reading in September in Dehiwala?

In Dehiwala, the average daily maximum UV index in September is 12. A UV Index value of 11, and more, symbolizes an excessive health risk from unprotected exposure to the UV radiation.
Average temperature in September - Dehiwala, Sri Lanka
  • Average high temperature in September: 30°C

Warmest months (with the highest average high temperature) are March and April (32°C).
Months with the lowest average high temperature are June, July, August, September, October, November and December (30°C).

  • Average low temperature in September: 25°C

Months with the highest average low temperature are May, June, July, August and September (25°C).
Coldest months (with the lowest average low temperature) are January and December (22°C).

Average rainfall in September - Dehiwala, Sri Lanka
  • Average rainfall in September: 236mm

The wettest month (with the highest rainfall) is May (382mm).
The driest month (with the lowest rainfall) is January (55mm).

Average rainfall days in September - Dehiwala, Sri Lanka
  • Average rainfall days in September: 14 days

The month with the highest number of rainy days is October (16 days).
Months with the lowest number of rainy days are January and February (5 days).

Average sea temperature in September - Dehiwala, Sri Lanka
  • Average sea temperature in September: 27.8°C

The best month for swimming (with the highest average sea temperature) is April (29.6°C).
The coldest month (with the lowest average sea temperature) is August (27.2°C).

Average daylight in September / Average sunshine in September - Dehiwala, Sri Lanka
  • Average daylight in September: 12.2h

Months with the longest days are June and July (Average daylight: 12.5h).
The month with shortest days is December (Average daylight: 11.7h).

  • Average sunshine in September: 6h

Months with most sunshine are February and March (Average sunshine: 9h).
Months with least sunshine are May, June, July, August, September and October (Average sunshine: 6).

Average UV index in September - Dehiwala, Sri Lanka
  • Average UV index in September: 12

Months with the highest UV index are February, March, April, May, June, July, August, September and October (UV index 12).
Months with the lowest UV index are January, November and December (UV index 11).

deutscheenglishespañolрусский中文