September weather forecastWattala, Sri Lanka
September weather for Wattala, Sri Lanka: The first month of the autumn, September, is also a moderately hot month in Wattala, Sri Lanka, with temperature in the range of an average low of 24.9°C (76.8°F) and an average high of 29.1°C (84.4°F). January through April, July, September, November and December, with an average maximum UV index of 7, are months with the highest UV index in Wattala, Sri Lanka.
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in Wattala, Sri Lanka, with temperature in the range of an average low of 24.9°C (76.8°F) and an average high of 29.1°C (84.4°F).Temperature
With September's arrival, Wattala notes an average high-temperature of a still warm 29.1°C (84.4°F), closely following the trend of the preceding month. Wattala maintains a near steady average temperature of 24.9°C (76.8°F) during the nights of September, demonstrating little drop from daytime highs.Heat index
The average heat index in September is evaluated at a very hot 35°C (95°F). Special measures are necessary to avoid heat cramps and heat exhaustion. Persistent activity could result in heatstroke.Note that heat index values are valued for light wind and location in the shade. Under direct sunshine, the heat index values might be elevated by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'felt air temperature', is a composite of temperature and humidity figures to convey how warm it feels. Additional elements encompassing metabolic differences, the degree of physical activity, and attire can impact the individual's perception of temperature. Consider that direct sun exposure can intensify the felt heat, adding potentially 15 Fahrenheit (8 Celsius) degrees to the heat index. Heat index values are particularly meaningful for babies and toddlers. Young ones often underestimate the need for rest and rehydration. Thirst appears late in dehydration - hence, it is important to keep hydrated, particularly during prolonged physical activities.
Sweat evaporation, driven by perspiration, is the method the human body uses to rid itself of excessive warmth. When the air holds a significant amount of moisture, the efficiency of the evaporation process is decreased, preventing the body from cooling down efficiently, leading to the sensation of overheating. Overheating dangers loom when the body's heat release mechanisms are overshadowed by excessive gain.
Humidity
The average relative humidity in September in Wattala is 81%.Rainfall
In Wattala, in September, it is raining for 26.9 days, with typically 206mm (8.11") of accumulated precipitation. In Wattala, Sri Lanka, during the entire year, the rain falls for 289.4 days and collects up to 2262mm (89.06") of precipitation.Sea temperature
In Wattala, the average seawater temperature in September is 27.8°C (82°F).Note: Swimming, diving, and similar water activities in temperatures ranging from 25°C (77°F) to 29°C (84.2°F) are seen as very agreeable and pleasurable for lengthy periods without discomfort.
Daylight
The average length of the day in September is 12h and 10min.On the first day of September, sunrise is at 06:02 and sunset at 18:17. On the last day of the month, sunrise is at 05:58 and sunset at 18:02 +0530.
Sunshine
The average sunshine in September in Wattala is 7.4h.UV index
The months with the highest UV index in Wattala are January through April, July, September, November and December, with an average maximum UV index of 7. A UV Index value of 6 to 7 symbolizes a high health vulnerability from exposure to the Sun's UV rays for the average person.Note: In September, an average UV index of 7 transforms into the following instructions:
Adhere to precautions and respect sun safety doctrines. Avoiding sunburn is vital. Make an effort to avoid direct sun exposure between 10 a.m. and 4 p.m., the peak period for UV radiation, and note that objects like parasols or canopies might not offer full sun protection. Experience reduced UV exposure by about half when donning a wide-brim hat. Attention! UV strength is notably upped by the reflection of sand and water.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Wattala, Sri Lanka
- Average high temperature in September: 29.1°C
The warmest months (with the highest average high temperature) are March and April (31.8°C).
The months with the lowest average high temperature are July and August (28.9°C).
- Average low temperature in September: 24.9°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 (23.1°C).
Average pressure in September
Wattala, Sri Lanka
- Average pressure in September: 1009.8mbar
The month with the highest atmospheric pressure is January (1011.6mbar).
The month with the lowest atmospheric pressure is May (1008.6mbar).
Average wind speed in September
Wattala, Sri Lanka
- Average wind speed in September: 13.2km/h
The windiest month (with the highest average wind speed) is June (15.1km/h).
The calmest month (with the lowest average wind speed) is March (8km/h).
Average humidity in September
Wattala, Sri Lanka
- Average humidity in September: 81%
The months with the highest relative humidity are June, July and August (83%).
The months with the lowest relative humidity are January and February (74%).
Average rainfall in September
Wattala, Sri Lanka
- Average rainfall in September: 206mm
The wettest month (with the highest rainfall) is June (341mm).
The driest month (with the least rainfall) is January (40mm).
Average rainfall days in September
Wattala, Sri Lanka
- Average rainfall days in September: 26.9 days
The month with the highest number of rainy days is August (30.2 days).
The month with the least rainy days is January (11.6 days).
Average sea temperature in September
Wattala, Sri Lanka
- Average sea temperature in September: 27.8°C
The best month for swimming (with the highest average sea temperature) is April (29.6°C).
The coldest month (with the lowest average sea temperature) is August (27.2°C).
Average daylight in September /
Average sunshine in September
Wattala, 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: 7h and 24min
The month with the most sunshine is January (Average sunshine: 9h and 6min).
The month with the least sunshine is November (Average sunshine: 6h and 42min).
Average sunshine days in September
Wattala, Sri Lanka
- Average sunshine days in September: 1.5 days
The month with the most sunshine days is January (17.2 days).
The months with the least sunshine days are June and August (0.3 days).
Average UV index in September
Wattala, Sri Lanka
- Average UV index in September: 7
The months with the highest UV index are January, February, March, April, July, September, November and December (UV index 7).
The months with the lowest UV index are May, June, August and October (UV index 6).
Average cloud cover in September
Wattala, Sri Lanka
- Average cloud cover in September: 55
The month with the most cloud cover is June (Cloud cover 57).
The month with the least cloud cover is January (Cloud cover 24).
Average visibility in September
Wattala, Sri Lanka
- Average visibility in September: 9km
The months with the highest visibility are January, February, March, April and December (10km).
The months with the lowest visibility are May, June, July, August, September, October and November (9km).





