September weather forecastKelanimulla, Sri Lanka
September
Weather in September
September, the first month of the autumn in Kelanimulla, is still a warm month, with temperature in the range of an average high of 29.1°C (84.4°F) and an average low of 24.9°C (76.8°F).Temperature
The advent of September sees the average high-temperature at a still moderately hot 29.1°C (84.4°F), subtly shifted from August's 28.9°C (84°F). During the month of September, Kelanimulla identifies an average nighttime low-temperature of 24.9°C (76.8°F), slightly lower than its daytime counterpart.Heat index
The heat index in September 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.Be advised, the heat index considers values for conditions in shade and with a light breeze. With exposure to direct sunshine, the heat index could climb by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'real feel', combines air temperature and relative humidity to represent a human perceived temperature equivalent. Elements such as metabolic variations, pregnancy, and physical exertion can shape one's weather perception. Taking into account that direct sunlight can boost the heat effect, the heat index may rise by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular importance 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.
The human body normally cools itself by perspiration. Excessive warmth is eliminated from the body by evaporation of sweat. In situations of high air temperature combined with high humidity (significant heat index), the body's ability to perspire is reduced, heightening the sense of warmth. If heat absorption isn't effectively countered by the body's cooling methods, body temperature surges, hinting at potential problems.
Humidity
In Kelanimulla, the average relative humidity in September is 81%.Rainfall
In September, the rain falls for 26.9 days. Throughout September, 206mm (8.11") of precipitation is accumulated. Throughout the year, there are 289.4 rainfall days, and 2262mm (89.06") of precipitation is accumulated.Daylight
The average length of the day in September is 12h and 10min.On the first day of the month, sunrise is at 06:02 and sunset at 18:17. On the last day of September, sunrise is at 05:58 and sunset at 18:02 +0530.
Sunshine
The average sunshine in September is 7.4h.UV index
January through April, July, September, November and December, with an average maximum UV index of 7, are months with the highest UV index. A UV Index of 6 to 7 symbolizes a high health risk from unsafe exposure to UV radiation for ordinary individuals.Note: The UV index of 7 in September translates into these instructions:
Guard against overexposure. Protection from sun-induced harm is essential. Avoid direct exposure to the Sun between 10 a.m. and 4 p.m., the peak period for UV radiation, noting that objects like parasols or canopies might not offer complete sun protection. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Kelanimulla, 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
Kelanimulla, 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
Kelanimulla, 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
Kelanimulla, 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
Kelanimulla, 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
Kelanimulla, 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 daylight in September /
Average sunshine in September
Kelanimulla, 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
Kelanimulla, 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
Kelanimulla, 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
Kelanimulla, 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
Kelanimulla, 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).





