September weather forecastJaffna, Sri Lanka
September
Weather in September
September is often characterized by significant rainfall, with a massive leap to 58mm (2.28") from the preceding month, over 15.5 days. Taking precedence, this is one key characteristic of September's weather pattern in Jaffna. Furthermore, conditions continue to be predominantly humid while sunlight hours slightly decrease. These alterations pave the way for an influx of cloudy days and occasional rains in the city.Temperature
The average high-temperature in Jaffna, Sri Lanka, in September aligns with the previous month. The September nights in Jaffna, Sri Lanka, show a slight decrease to a mean low-temperature of 27.5°C (81.5°F).Heat index
The heat index in September is calculated to be a tropical 34°C (93.2°F). Take more caution, heat exhaustion and heat cramps may occur. Long-lasting activity may cause heatstroke.Take note of the fact that heat index values are based on shaded circumstances with light airflows. 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', combines both the air temperature and the humidity level to give a perceived human temperature. Factors including metabolic differences, physical activity, and clothing are additional elements that influence the individual's temperature experience. Direct exposure to the sun's rays can enhance the felt temperature, increasing the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values hold great significance to children. Younglings are generally more in peril than adults due to their reduced perspiration. Coupled with a larger skin surface relative to their tiny bodies and greater heat production because of their activity, they become more at risk.
Humidity
The months with the highest humidity are May, August and September, with an average relative humidity of 79%.Rainfall
In Jaffna, during September, the rain falls for 15.5 days and regularly aggregates up to 58mm (2.28") of precipitation. In Jaffna, during the entire year, the rain falls for 148.6 days and collects up to 769mm (30.28") of precipitation.Sea temperature
In Jaffna, the average seawater temperature in September is 29°C (84.2°F).Note: Water temperature between 25°C (77°F) and 29°C (84.2°F) is perceived as agreeably warm, making all water activities enjoyable without the risk of discomfort over lengthy durations.
Daylight
The average length of the day in September in Jaffna is 12h and 11min.On the first day of the month, sunrise is at 06:00 and sunset at 18:18. On the last day of September, sunrise is at 05:58 and sunset at 18:01 +0530.
Sunshine
In Jaffna, Sri Lanka, the average sunshine in September 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 value of 6 to 7 symbolizes a high threat to health from exposure to the Sun's UV rays for average individuals.Note: A maximum UV index of 7 in September translates into the following recommendations:
Shun overexposure. Protection from sun ravages is indispensable. Seek shade and limit direct sun exposure between 10 a.m. and 4 p.m., the peak period for UV radiation. Keep in mind that shade structures like parasols or canopies do not offer complete sun protection. To cut down UV radiation exposure by about half, sport a wide-brim hat. Alert! UV radiation becomes sharper due to reflections from sand and water.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
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).
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).
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).
Average humidity in September
Jaffna, Sri Lanka
- Average humidity in September: 79%
The months with the highest relative humidity are May, August and September (79%).
The month with the lowest relative humidity is March (75%).
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).
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).
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).
Average daylight in September /
Average sunshine in September
Jaffna, Sri Lanka
- Average daylight in September: 12h and 12min
The month with the longest days is June (Average daylight: 12h and 42min).
The month with the shortest days is December (Average daylight: 11h and 36min).
- Average sunshine in September: 10h and 12min
The month with the most sunshine is June (Average sunshine: 11h and 36min).
The month with the least sunshine is December (Average sunshine: 5h and 30min).
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).
Average UV index in September
Jaffna, Sri Lanka
- Average UV index in September: 7
The 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).
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).
Average visibility in September
Jaffna, Sri Lanka
- Average visibility in September: 10km
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (10km).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (10km).
