September weather forecastYatiwawala, Sri Lanka
September
Weather in September
The first month of the autumn, September, is still a warm month in Yatiwawala, Sri Lanka, with temperature in the range of an average high of 29.5°C (85.1°F) and an average low of 21.1°C (70°F).Temperature
The onset of September brings with it an average high-temperature of a still moderately hot 29.5°C (85.1°F), showing a negligible variation from the month before. During the nights in September, the temperature in Yatiwawala averages to a pleasant 21.1°C (70°F).Heat index
The heat index value for September is computed to be a torrid 35°C (95°F). Exercise increased caution, heat cramps and heat exhaustion are potential hazards. Continuous activity could lead to heatstroke.The standards for the heat index are set for locations in shade and under light breezes. The heat index can potentially augment by 15 Fahrenheit (8 Celsius) degrees due to direct sunlight.
Note: The heat index, also known as 'felt air temperature' or 'feels like', binds temperature metrics with humidity values to give a sense of the actual warmth. This effect tends to be personal, with the weather perception differing among individuals due to variations in body mass, height, and exertion. Keep in mind that direct sunshine exposure can amplify the weather's effects, possibly increasing the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly meaningful for babies and toddlers. Children often overlook the necessity for resting and fluid replenishment. Thirst is a late sign of dehydration - thus, it is critical to stay hydrated, especially during extended periods of physical activities.
Perspiration, followed by sweat evaporation, is the human body's chief method to maintain a balanced temperature. When there is abundant moisture in the air, the body's cooling through the evaporation process becomes less effective, leading to the sensation of overheating. Heat-related disorders may develop if heat gain in the body overshadows its cooling capacity, leading to elevated temperatures.
Humidity
In September, the average relative humidity is 77%.Rainfall
In Yatiwawala, in September, it is raining for 23.4 days, with typically 118mm (4.65") of accumulated precipitation. In Yatiwawala, during the entire year, the rain falls for 278.4 days and collects up to 1466mm (57.72") of precipitation.Daylight
The average length of the day in September is 12h and 10min.On the first day of the month, sunrise is at 05:59 and sunset at 18:15. On the last day of September, sunrise is at 05:55 and sunset at 17:59 +0530.
Sunshine
In September, the average sunshine is 10.3h.UV index
The months with the highest UV index in Yatiwawala are January through September, November and December, with an average maximum UV index of 6. A UV Index value of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV rays for ordinary individuals.Note: In September, the maximum UV index of 6 suggests this advice:
Conform to measures and uphold sun safety traditions. Warding off skin and eye harm is necessary. Limit direct sun exposure especially between 10 a.m. and 4 p.m., when UV radiation is at its peak. However, keep in mind that shade structures may not provide full sun protection. Wearing a wide-brim hat can block approximately 50% of UV radiation, protecting the eyes.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Yatiwawala, Sri Lanka
- Average high temperature in September: 29.5°C
The warmest month (with the highest average high temperature) is March (31.5°C).
The month with the lowest average high temperature is December (27.5°C).
- Average low temperature in September: 21.1°C
The months with the highest average low temperature are May and June (21.8°C).
The coldest month (with the lowest average low temperature) is February (18.1°C).
Average pressure in September
Yatiwawala, Sri Lanka
- Average pressure in September: 1009.3mbar
The month with the highest atmospheric pressure is January (1011.8mbar).
The month with the lowest atmospheric pressure is June (1008.1mbar).
Average wind speed in September
Yatiwawala, Sri Lanka
- Average wind speed in September: 10.8km/h
The windiest month (with the highest average wind speed) is June (13.5km/h).
The calmest month (with the lowest average wind speed) is April (4.7km/h).
Average humidity in September
Yatiwawala, Sri Lanka
- Average humidity in September: 77%
The month with the highest relative humidity is December (84%).
The month with the lowest relative humidity is March (74%).
Average rainfall in September
Yatiwawala, Sri Lanka
- Average rainfall in September: 118mm
The wettest month (with the highest rainfall) is October (301mm).
The driest month (with the least rainfall) is January (38mm).
Average rainfall days in September
Yatiwawala, Sri Lanka
- Average rainfall days in September: 23.4 days
The month with the highest number of rainy days is May (28.6 days).
The month with the least rainy days is January (14.1 days).
Average daylight in September /
Average sunshine in September
Yatiwawala, 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: 10h and 18min
The month with the most sunshine is June (Average sunshine: 10h and 48min).
The month with the least sunshine is December (Average sunshine: 5h and 42min).
Average sunshine days in September
Yatiwawala, Sri Lanka
- Average sunshine days in September: 3.9 days
The month with the most sunshine days is January (14.8 days).
The month with the least sunshine days is May (1.2 days).
Average UV index in September
Yatiwawala, Sri Lanka
- Average UV index in September: 6
The months with the highest UV index are January, February, March, April, May, June, July, August, September, November and December (UV index 6).
The month with the lowest UV index is October (UV index 5).
Average cloud cover in September
Yatiwawala, Sri Lanka
- Average cloud cover in September: 34
The months with the most cloud cover are November and December (Cloud cover 47).
The month with the least cloud cover is March (Cloud cover 27).
Average visibility in September
Yatiwawala, Sri Lanka
- Average visibility in September: 9km
The months with the highest visibility are June, July and August (10km).
The months with the lowest visibility are January, February, March, April, November and December (8km).








