September weather forecast and climate
Jaffna, Sri Lanka

Weather in September

September, the first month of the autumn, in Jaffna, is also a moderately hot month, with temperature in the range of an average high of 28.8°C (83.8°F) and an average low of 27.5°C (81.5°F).

Temperature

In Jaffna, the average high-temperature remains equal as in August - a still moderately hot 28.8°C (83.8°F). In Jaffna, Sri Lanka,, the average low-temperature is 27.5°C (81.5°F).

Heat index

In September, the average heat index is appraised at a hot 34°C (93.2°F). Take special precautions - heat exhaustion and heat cramps are expected. Heatstroke may occur with lengthy activity.
Take into consideration that the heat index values are calculated for shade and light wind conditions. With 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 'apparent temperature', 'real feel', 'felt air temperature', or 'feels like', is a measure that combines air temperature and relative humidity into a single value that indicates how hot the weather feels. Additional factors like pregnancy, wind, differences in body mass, height, and shape, and activity influence one's weather impression. 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 especially crucial for babies and toddlers. 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.

Humidity

May, August and September, with an average relative humidity of 79%, are most humid months in Jaffna.

Rainfall

In Jaffna, during 15.5 rainfall days, 58mm (2.28") of precipitation is typically accumulated. Throughout the year, there are 148.6 rainfall days, and 769mm (30.28") of precipitation is accumulated.

Sea temperature

In Jaffna, the average water temperature is 29°C (84.2°F).
Note: 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.

Daylight

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

Sunshine

In Jaffna, the average sunshine is 10.2h.

UV index

January through October and December, with an average maximum UV index of 7, are months with the highest UV index in Jaffna. A UV Index reading of 6 to 7 represents a high health hazard from unprotected exposure to the Sun's UV rays for the average person.
Note: In September, the average maximum UV index of 7 translate into the following recommendations:
Take precautions and utilize sun safety practices. Protection against the skin and eye damage is required. 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. 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. Beware! The reflection of water and sand dramatically increases exposure to the UV rays.
[Resources]

FAQ

What is the temperature in September in Jaffna?

In Jaffna, Sri Lanka, in September, the average high-temperature is 28.8°C (83.8°F), and the average low-temperature is 27.5°C (81.5°F). The average heat index (a.k.a. 'felt air temperature', 'real feel'), which factors the actual air temperature with the relative humidity, in September is appraised at 34°C (93.2°F).

What are the most humid months in Jaffna?

May, August and September, with an average relative humidity of 79%, are most humid months in Jaffna.

What is the average humidity in September in Jaffna?

In Jaffna, the average relative humidity in September is 79%.

How many days does it rain in September in Jaffna?

In September, in Jaffna, the rain falls for 15.5 days. Throughout September, 58mm (2.28") of precipitation is accumulated.

What is the water temperature in September in Jaffna?

In Jaffna, Sri Lanka, in September, the average water temperature is 29°C (84.2°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 Jaffna have in September?

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

How long on average sun shines in September in Jaffna?

The average sunshine in September in Jaffna, Sri Lanka, is 10.2h.

When is the highest UV index in Jaffna?

Months with the highest UV index in Jaffna, Sri Lanka, are January through October and December, with an average maximum UV index of 7.

What is the UV index reading in September in Jaffna?

The average daily maximum UV index in September in Jaffna is 7. A UV Index value of 6 to 7 symbolizes a high health risk from the exposure to the Sun's UV radiation.

Average temperature in September
Jaffna, Sri Lanka

Average temperature in September - Jaffna, Sri Lanka
  • Average high temperature in September: 28.8°C

The warmest month (with the highest average high temperature) is April (30.4°C).
The month with the lowest average high temperature is January (26.8°C).

  • Average low temperature in September: 27.5°C

The month with the highest average low temperature is May (29°C).
The coldest month (with the lowest average low temperature) is January (25.5°C).

[Resources]

Average pressure in September
Jaffna, Sri Lanka

Average pressure in September - Jaffna, Sri Lanka
  • Average pressure in September: 1007.6mbar

The month with the highest atmospheric pressure is January (1012.5mbar).
The month with the lowest atmospheric pressure is June (1005.9mbar).

[Resources]

Average wind speed in September
Jaffna, Sri Lanka

Average wind speed in September - Jaffna, Sri Lanka
  • Average wind speed in September: 28.3km/h

The windiest month (with the highest average wind speed) is June (33.8km/h).
The calmest months (with the lowest average wind speed) are March and April (16.7km/h).

[Resources]

Average humidity in September
Jaffna, Sri Lanka

Average humidity in September - Jaffna, Sri Lanka
  • Average humidity in September: 79%

Months with the highest relative humidity are May, August and September (79%).
The month with the lowest relative humidity is March (75%).

[Resources]

Average rainfall in September
Jaffna, Sri Lanka

Average rainfall in September - Jaffna, Sri Lanka
  • Average rainfall in September: 58mm

The wettest month (with the highest rainfall) is October (191mm).
The driest month (with the least rainfall) is March (13mm).

[Resources]

Average rainfall days in September
Jaffna, Sri Lanka

Average rainfall days in September - Jaffna, Sri Lanka
  • Average rainfall days in September: 15.5 days

The month with the highest number of rainy days is October (22.6 days).
The month with the least rainy days is March (5.8 days).

[Resources]

Average sea temperature in September
Jaffna, Sri Lanka

Average sea temperature in September - Jaffna, Sri Lanka
  • Average sea temperature in September: 29°C

The best month for swimming (with the highest average sea temperature) is April (30.1°C).
The coldest month (with the lowest average sea temperature) is January (26.8°C).

[Resources]

Average daylight in September /
Average sunshine in September
Jaffna, Sri Lanka

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

The month with the longest days is June (Average daylight: 12.7h).
Months with the shortest days are January and December (Average daylight: 11.6h).

  • Average sunshine in September: 10.2h

The month with the most sunshine is June (Average sunshine: 11.6h).
The month with the least sunshine is December (Average sunshine: 5.5h).

[Resources]

Average sunshine days in September
Jaffna, Sri Lanka

Average sunshine days in September - Jaffna, Sri Lanka
  • Average sunshine days in September: 13.8 days

The month with the most sunshine days is March (23.9 days).
The month with the least sunshine days is November (6.3 days).

[Resources]

Average UV index in September
Jaffna, Sri Lanka

Average UV index in September - Jaffna, Sri Lanka
  • Average UV index in September: 7

Months with the highest UV index are January, February, March, April, May, June, July, August, September, October and December (UV index 7).
The month with the lowest UV index is November (UV index 6).

[Resources]

Average cloud cover in September
Jaffna, Sri Lanka

Average cloud cover in September - Jaffna, Sri Lanka
  • Average cloud cover in September: 30

The month with the most cloud cover is December (Cloud cover 47).
The month with the least cloud cover is March (Cloud cover 16).

[Resources]

Average visibility in September
Jaffna, Sri Lanka

Average visibility in September - Jaffna, Sri Lanka
  • Average visibility in September: 10km

Months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (10km).
Months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (10km).

[Resources]

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location
* you will be automatically redirected to the weather forecast for your location