September weather forecastMallavi, Sri Lanka
September
Weather in September
September, the first month of the autumn in Mallavi, is still a warm month, with an average temperature ranging between max 29.9°C (85.8°F) and min 27°C (80.6°F).Temperature
Mallavi, Sri Lanka, starts September with an average high-temperature of a still warm 29.9°C (85.8°F), a minor shift from August's 29.8°C (85.6°F). Mallavi, during September nights, witnesses an average temperature marginally cooler than its daytime highs, at a still moderately hot 27°C (80.6°F).Heat index
The heat index for September is estimated at a very hot 37°C (98.6°F). Implement additional preventive actions, heat cramps and heat exhaustion are potential hazards. Heatstroke could follow prolonged activity.From a standpoint of the heat index, values pertain to shaded conditions and mild breezes. The direct sun can potentially cause the heat index to increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'feels like', is the result of factoring in humidity to the air temperature, indicating perceived warmth. The impact of weather is personal, differing among a variety of people based on differences in body mass, height, and the level of physical exertion. When you're directly under the sun's rays, remember that the heat index may surge by 15 Fahrenheit (8 Celsius) degrees. Heat index values are essentially critical for children. Young ones are generally more prone to risk than adults due to their reduced ability to sweat. Their large skin surface area relative to their diminutive bodies and elevated heat production from their activities further enhance this risk.
Evaporation of sweat is the main factor behind the cooling effect of perspiration in the human body. With higher relative humidity, the rate of evaporation is reduced, resulting in increased heat retention in the body compared to drier air. Heat absorption that surpasses the body's shedding capability can lead to overheating and varying levels of dehydration.
Humidity
The average relative humidity in September in Mallavi is 77%.Rainfall
In Mallavi, during September, the rain falls for 15.5 days and regularly aggregates up to 45mm (1.77") of precipitation. In Mallavi, during the entire year, the rain falls for 181.2 days and collects up to 849mm (33.43") of precipitation.Daylight
In Mallavi, Sri Lanka, the average length of the day in September is 12h and 10min.On the first day of the month, sunrise is at 06:00 and sunset at 18:17. On the last day of September, sunrise is at 05:57 and sunset at 18:00 +0530.
Sunshine
The average sunshine in September in Mallavi is 9.7h.UV index
January through October and December, with an average maximum UV index of 7, are months with the highest UV index. A UV Index estimate of 6 to 7 represents a high health hazard from exposure to the Sun's UV rays for the ordinary person.Note: The daily maximum UV index of 7 in September interprets into the following advice:
Take precautions and utilize sun safety practices. Protection against skin and eye damage is required. 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. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Mallavi, Sri Lanka
- Average high temperature in September: 29.9°C
The warmest month (with the highest average high temperature) is April (31.4°C).
The month with the lowest average high temperature is January (28.4°C).
- Average low temperature in September: 27°C
The month with the highest average low temperature is May (28.1°C).
The coldest month (with the lowest average low temperature) is February (23.9°C).
Average pressure in September
Mallavi, Sri Lanka
- Average pressure in September: 1008mbar
The month with the highest atmospheric pressure is January (1012.2mbar).
The month with the lowest atmospheric pressure is June (1006.5mbar).
Average wind speed in September
Mallavi, Sri Lanka
- Average wind speed in September: 27.1km/h
The windiest month (with the highest average wind speed) is June (32.4km/h).
The calmest month (with the lowest average wind speed) is April (15.4km/h).
Average humidity in September
Mallavi, Sri Lanka
- Average humidity in September: 77%
The months with the highest relative humidity are November and December (79%).
The month with the lowest relative humidity is March (75%).
Average rainfall in September
Mallavi, Sri Lanka
- Average rainfall in September: 45mm
The wettest month (with the highest rainfall) is November (207mm).
The driest month (with the least rainfall) is June (28mm).
Average rainfall days in September
Mallavi, Sri Lanka
- Average rainfall days in September: 15.5 days
The months with the highest number of rainy days are October and November (23.8 days).
The month with the least rainy days is February (9.1 days).
Average daylight in September /
Average sunshine in September
Mallavi, Sri Lanka
- Average daylight in September: 12h and 12min
The month with the longest days is June (Average daylight: 12h and 36min).
The month with the shortest days is December (Average daylight: 11h and 36min).
- Average sunshine in September: 9h and 42min
The month with the most sunshine is June (Average sunshine: 11h and 18min).
The months with the least sunshine are November and December (Average sunshine: 5h and 42min).
Average sunshine days in September
Mallavi, Sri Lanka
- Average sunshine days in September: 11.4 days
The month with the most sunshine days is March (19 days).
The month with the least sunshine days is November (4.4 days).
Average UV index in September
Mallavi, 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
Mallavi, Sri Lanka
- Average cloud cover in September: 33
The month with the most cloud cover is December (Cloud cover 44).
The month with the least cloud cover is March (Cloud cover 18).
Average visibility in September
Mallavi, Sri Lanka
- Average visibility in September: 10km
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October and December (10km).
The month with the lowest visibility is November (9km).





