September weather forecastDevinuwara, Sri Lanka
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in Devinuwara, Sri Lanka, with an average temperature fluctuating between 25.3°C (77.5°F) and 29.1°C (84.4°F).Temperature
The month of September, characterized by an average high of 29.1°C (84.4°F) and a low of 25.3°C (77.5°F), is recognized as the coldest.Heat index
During September, the heat index is appraised at a sweltering 35°C (95°F). Exercise increased caution, heat cramps and heat exhaustion are potential hazards. Continuous activity could lead to heatstroke.Understanding the heat index involves considering values for shaded locales with light wind. A rise of up to 15 Fahrenheit (8 Celsius) degrees in the heat index could result from direct sunlight.
Note: The heat index, also known as 'real feel' or 'felt air temperature', is a fusion of air temperature and moisture levels to demonstrate the sensation of heat. An individual's temperature experience can be influenced by extra factors, including metabolic differences, activity levels, and clothing. Be mindful that being in direct sunlight might mean feeling hotter, with the heat index rising by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are essentially critical for children. Kids frequently fail to realize the necessity for resting and hydrating. Thirst is an advanced indication of dehydration - hence, maintaining hydration, especially during extended physical activities, becomes essential.
Perspiration is the human body's physiological response to high temperatures and is an attempt to lower body temperature through evaporation of sweat. High relative humidity reduces the evaporation rate, resulting in a lower heat removal rate from the body, causing the perception of being overheated. When heat surpasses the body's release mechanisms, dehydration and overheating risks become pronounced.
Humidity
The months with the highest humidity are May, September and November, with an average relative humidity of 81%.Rainfall
In September, the rain falls for 13.2 days. Throughout September, 48mm (1.89") of precipitation is accumulated. In Devinuwara, during the entire year, the rain falls for 180 days and collects up to 509mm (20.04") of precipitation.Daylight
The average length of the day in September is 12h and 9min.On the first day of September, sunrise is at 06:00 and sunset at 18:14. On the last day of the month, sunrise is at 05:55 and sunset at 17:59 +0530.
Sunshine
The average sunshine in September is 8.6h.UV index
January through December, with an average maximum UV index of 7, are months with the highest UV index. January through December, with an average maximum UV index of 7, are months with the lowest UV index. A UV Index of 6 to 7 symbolizes a high health hazard from exposure to the Sun's UV radiation for the ordinary person.Note: In September, the maximum UV index of 7 transforms into these recommendations:
Enforce precautions and stick to sun safety measures. Preservation from skin and eye damage is essential. The time between 10 a.m. and 4 p.m. is when UV radiation is at its peak. Limit exposure to direct sunlight during these hours. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Devinuwara, Sri Lanka
- Average high temperature in September: 29.1°C
The warmest months (with the highest average high temperature) are March and April (31.1°C).
The month with the lowest average high temperature is September (29.1°C).
- Average low temperature in September: 25.3°C
The month with the highest average low temperature is May (26.3°C).
The coldest month (with the lowest average low temperature) is January (23°C).
Average pressure in September
Devinuwara, Sri Lanka
- Average pressure in September: 1010.2mbar
The month with the highest atmospheric pressure is January (1011.4mbar).
The month with the lowest atmospheric pressure is May (1008.9mbar).
Average wind speed in September
Devinuwara, Sri Lanka
- Average wind speed in September: 16.3km/h
The windiest month (with the highest average wind speed) is July (18.9km/h).
The calmest month (with the lowest average wind speed) is January (9km/h).
Average humidity in September
Devinuwara, Sri Lanka
- Average humidity in September: 81%
The months with the highest relative humidity are May, September and November (81%).
The months with the lowest relative humidity are January and February (77%).
Average rainfall in September
Devinuwara, Sri Lanka
- Average rainfall in September: 48mm
The wettest month (with the highest rainfall) is November (66mm).
The driest month (with the least rainfall) is January (22mm).
Average rainfall days in September
Devinuwara, Sri Lanka
- Average rainfall days in September: 13.2 days
The month with the highest number of rainy days is November (19.8 days).
The month with the least rainy days is June (10.7 days).
Average daylight in September /
Average sunshine in September
Devinuwara, 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 48min).
- Average sunshine in September: 8h and 36min
The month with the most sunshine is April (Average sunshine: 9h and 42min).
The month with the least sunshine is December (Average sunshine: 6h and 54min).
Average sunshine days in September
Devinuwara, Sri Lanka
- Average sunshine days in September: 14.5 days
The month with the most sunshine days is July (17.8 days).
The month with the least sunshine days is November (7.8 days).
Average UV index in September
Devinuwara, 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, November and December (UV index 7).
The months with the lowest UV index are January, February, March, April, May, June, July, August, September, October, November and December (UV index 7).
Average cloud cover in September
Devinuwara, Sri Lanka
- Average cloud cover in September: 50
The month with the most cloud cover is June (Cloud cover 53).
The month with the least cloud cover is February (Cloud cover 26).
Average visibility in September
Devinuwara, 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).





