September weather forecastDemodara, Sri Lanka
September weather forecast for Demodara, Sri Lanka: The first month of the autumn, September, is also a moderately hot month in Demodara, Sri Lanka, with an average temperature ranging between max 27.1°C (80.8°F) and min 18.7°C (65.7°F). In Demodara, in September, it is raining for 25.5 days, with typically 182mm (7.17") of accumulated precipitation.
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in Demodara, Sri Lanka, with an average temperature ranging between max 27.1°C (80.8°F) and min 18.7°C (65.7°F).Temperature
Demodara begins September with an average high-temperature of a still moderately hot 27.1°C (80.8°F), echoing August. During the month of September, an average low-temperature of 18.7°C (65.7°F) is recorded.Heat index
The average heat index in September is calculated to be a tropical 30°C (86°F). Continuous activity in exposure could lead to a feeling of fatigue and heat cramps.Heat index's context suggests values are appropriate for shady areas and slight breezes. Direct sunlight exposure may cause a 15 Fahrenheit (8 Celsius) degrees rise in the heat index.
Note: The heat index, also known as 'feels like' or 'apparent temperature', melds the effects of warmth and moisture to generate a feeling of heat. This effect is personal, influenced by the individual's physical activity and heat sensitivity, shaped by factors including wind, attire, and metabolic variations. When in direct sunlight, one should be cautious as it can raise the heat index by as much as 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical to babies and toddlers. Young individuals are typically more threatened than adults due to their reduced perspiration. Also, the larger skin surface proportionate to their small bodies and the increased heat from their activities magnify their risk.
Humidity
The average relative humidity in September is 82%.Rainfall
In Demodara, in September, it is raining for 25.5 days, with typically 182mm (7.17") of accumulated precipitation. In Demodara, during the entire year, the rain falls for 297.4 days and collects up to 2784mm (109.61") of precipitation.Daylight
In September, the average length of the day is 12h and 10min.On the first day of September, sunrise is at 05:58 and sunset at 18:13. On the last day of the month, sunrise is at 05:53 and sunset at 17:57 +0530.
Sunshine
In Demodara, Sri Lanka, the average sunshine in September is 9.5h.UV index
The months with the highest UV index are February through September, with an average maximum UV index of 6. A UV Index of 6 to 7 symbolizes a high threat to health from unsafe exposure to UV radiation for average individuals.Note: An average maximum UV index of 6 in September leads to these recommendations:
Use measures and accept sun safety conventions. Guarding against skin and eye trauma is of high priority. Between 10 a.m. and 4 p.m., the Sun's UV radiation is at its peak. Limit your exposure to direct sunlight during these hours. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Demodara, Sri Lanka
- Average high temperature in September: 27.1°C
The warmest month (with the highest average high temperature) is April (27.6°C).
The month with the lowest average high temperature is December (24.3°C).
- Average low temperature in September: 18.7°C
The month with the highest average low temperature is May (19.1°C).
The coldest month (with the lowest average low temperature) is February (15.3°C).
Average pressure in September
Demodara, Sri Lanka
- Average pressure in September: 1009.5mbar
The month with the highest atmospheric pressure is January (1011.7mbar).
The month with the lowest atmospheric pressure is June (1008.3mbar).
Average wind speed in September
Demodara, Sri Lanka
- Average wind speed in September: 7.1km/h
The windiest month (with the highest average wind speed) is June (9.1km/h).
The calmest month (with the lowest average wind speed) is April (3.3km/h).
Average humidity in September
Demodara, Sri Lanka
- Average humidity in September: 82%
The month with the highest relative humidity is November (89%).
The month with the lowest relative humidity is March (80%).
Average rainfall in September
Demodara, Sri Lanka
- Average rainfall in September: 182mm
The wettest month (with the highest rainfall) is October (656mm).
The driest month (with the least rainfall) is January (85mm).
Average rainfall days in September
Demodara, Sri Lanka
- Average rainfall days in September: 25.5 days
The month with the highest number of rainy days is May (29.8 days).
The month with the least rainy days is February (16.3 days).
Average daylight in September /
Average sunshine in September
Demodara, Sri Lanka
- Average daylight in September: 12h and 12min
The month with the longest days is June (Average daylight: 12h and 30min).
The month with the shortest days is December (Average daylight: 11h and 42min).
- Average sunshine in September: 9h and 30min
The month with the most sunshine is June (Average sunshine: 10h and 0min).
The month with the least sunshine is December (Average sunshine: 4h and 36min).
Average sunshine days in September
Demodara, Sri Lanka
- Average sunshine days in September: 2.2 days
The month with the most sunshine days is February (11 days).
The month with the least sunshine days is May (0.8 days).
Average UV index in September
Demodara, Sri Lanka
- Average UV index in September: 6
The months with the highest UV index are February, March, April, May, June, July, August and September (UV index 6).
The months with the lowest UV index are January, October, November and December (UV index 5).
Average cloud cover in September
Demodara, Sri Lanka
- Average cloud cover in September: 44
The month with the most cloud cover is November (Cloud cover 63).
The months with the least cloud cover are July and August (Cloud cover 42).
Average visibility in September
Demodara, Sri Lanka
- Average visibility in September: 8km
The months with the highest visibility are June, July and August (9km).
The months with the lowest visibility are November and December (6km).





