Colombo
Sri Lanka
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Colombo, Sri Lanka

Statues on the Seema Malaka Temple in Colombo, Sri Lanka, overlooking the Beira Lake, and a view of the tall buildings of Colombo
Statues on the Seema Malaka Temple in Colombo, Sri Lanka, overlooking the Beira Lake, and a view of the tall buildings of Colombo
The first month of the autumn, Septiembre, is still a tropical month in Colombo, Sri Lanka, with average temperature varying between 30.2°C (86.4°F) and 24.8°C (76.6°F).

Temperature

In Septiembre, the average high-temperature is almost the same as in Agosto - a still tropical 30.2°C (86.4°F). In Colombo, the average low-temperature is 24.8°C (76.6°F).

Heat index

The average heat index is evaluated at a very hot 37.7°C (99.9°F). Take extra precautions, as heat cramps and heat exhaustion are possible. Sustained activity may result in heatstroke.
Take into consideration that the heat index values are calculated for shade and light wind conditions. With the exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature', 'feels like', 'real feel', or 'apparent temperature', is a calculated temperature value of how hot it feels when the moisture in the air is factored in. This effect is individual, with diverse people perceiving weather differently for numerous reasons (pregnancy, metabolic differences, clothing), and activity. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.
The human body normally cools itself by perspiration. Excessive warmth is eliminated from the body by evaporation of sweat. When the relative humidity is high, the evaporation rate is reduced. The warmth is removed from the body at a lower rate, causing the body to retain more heat than it would in dry air. When heat gain exceeds the level the body can remove, body temperature begins to rise, and heat-related illnesses and disorders may develop.

Humidity

In Colombo, the average relative humidity is 78%.

Rainfall

In Colombo, in Septiembre, it is raining for 15 days, with typically 245.4mm (9.66") of accumulated precipitation. Throughout the year, there are 145 rainfall days, and 2523.7mm (99.36") of precipitation is accumulated.

Sea temperature

In Colombo, the average seawater temperature is 27.8°C (82°F).
Note: 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 Septiembre, the average length of the day in Colombo, Sri Lanka, is 12.2h.

Sunshine

With an average of 6.3h of sunshine, Septiembre has the least sunshine of the year.

UV index

Months with the highest UV index are Febrero through Octubre, with an average maximum UV index of 12. A UV Index value of 11, and more, symbolizes an excessive health risk from the exposure to the Sun's UV radiation for average individuals.
Note: The average daily UV index of 12 in Septiembre transform into the following instructions:
Take all necessary precautions, as unprotected skin can burn in minutes. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun. Even on cloudy days, a sunscreen with a minimum 30 sun protection factor should be generously applied and frequently re-applied, including after every swim or outdoor exercise. Beware! The reflection of water and sand dramatically increases exposure to the UV rays.

What is the temperature in Septiembre in Colombo?

The average high-temperature, in Septiembre, in Colombo, Sri Lanka, is 30.2°C (86.4°F), while the average low-temperature is 24.8°C (76.6°F). In Septiembre, the average heat index (a.k.a. 'real feel', 'felt air temperature'), that calculates temperature value influenced by the moisture in the air, is calculated to 37.7°C (99.9°F).

What is the average humidity in Septiembre in Colombo?

The average relative humidity in Septiembre in Colombo, Sri Lanka, is 78%.

How much does it rain in Colombo in Septiembre?

In Colombo, Sri Lanka, during Septiembre, the rain falls for 15 days and regularly aggregates up to 245.4mm (9.66") of precipitation.

What is the water temperature in Septiembre in Colombo?

In Septiembre, the average sea temperature in Colombo, Sri Lanka, is 27.8°C (82°F). Water temperature between 25°C (77°F) and 29°C (84.2°F) is regarded as very warm and enjoyable by all. With these temperatures, water activities are pleasurable, without feeling uncomfortable for prolonged periods.

How many hours of daylight does Colombo have in Septiembre?

The average length of the day in Septiembre in Colombo, Sri Lanka, is 12.2h.

What is the month with the least sunshine in Colombo?

The month with the least sunshine is Septiembre, with an average of 6.3h of sunshine.

How long on average sun shines in Septiembre in Colombo?

In Septiembre, the average sunshine in Colombo is 6.3h.

What are the months with the highest UV index in Colombo?

Months with the highest UV index in Colombo, Sri Lanka, are Febrero through Octubre, with an average maximum UV index of 12.

How high is the UV index in Septiembre in Colombo?

In Septiembre, the average daily maximum UV index in Colombo is 12. A UV Index of 11, and more, symbolizes an ultimate hazard to health from the exposure to the Sun's UV rays.
Average temperature in September - Colombo, Sri Lanka
  • Average high temperature in September: 30.2°C

The warmest month (with the highest average high temperature) is April (31.8°C).
Months with the lowest average high temperature are July, August and October (30°C).

  • Average low temperature in September: 24.8°C

Months with the highest average low temperature are May and June (25.5°C).
The coldest month (with the lowest average low temperature) is January (22.3°C).

Average humidity in September - Colombo, Sri Lanka
  • Average humidity in September: 78%

The month with the highest relative humidity is June (79%).
Months with the lowest relative humidity are January and February (69%).

Average rainfall in September - Colombo, Sri Lanka
  • Average rainfall in September: 245.4mm

The wettest month (with the highest rainfall) is November (414.4mm).
The driest month (with the lowest rainfall) is January (58.2mm).

Average rainfall days in September - Colombo, Sri Lanka
  • Average rainfall days in September: 15 days

The month with the highest number of rainy days is October (17 days).
Months with the lowest number of rainy days are January and February (5 days).

Average sea temperature in September - Colombo, 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 - Colombo, 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: 6.3h

The month with most sunshine is March (Average sunshine: 8.9h).
The month with least sunshine is September (Average sunshine: 6.3h).

Average UV index in September - Colombo, 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).