Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
September
Weather in September
Temperature
September reports an average high-temperature of a still hot 33.9°C (93°F), slightly varied from August's 33.7°C (92.7°F). Nighttime temperature dips to a mean of 24.1°C (75.4°F) during September.Heat index
In September, the heat index is appraised at a blazing hot 45°C (113°F). Take note: Heat exhaustion and heat cramps are expected. Heatstroke can occur with prolonged effort.Records show heat index calculations are tailored for shaded regions and mild winds. Exposure to unobstructed sunshine could lead to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'feels like', reflects the blend of air temperature and relative humidity to give a temperature impression. One's perception of weather can be shaped by other factors, involving metabolic differences, pregnancy, and physical exertion. Given direct exposure to sunlight, one might experience a rise in the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular significance for children. Typically, children face more danger than adults as they usually perspire less. Their larger skin surface relative to their small bodies and increased heat output from their activities enhance their risk.
Perspiration is the human body's physiological response to high temperatures and is an attempt to lower body temperature through evaporation of sweat. When the level of relative humidity is elevated, evaporation diminishes, causing more warmth to be retained in the body than in dry air. With body temperatures on the rise, inefficient heat shedding can lead to dehydration and its associated complications.
Humidity
The months with the lowest humidity are June through September, with an average relative humidity of 67%.Rainfall
In Nilaveli, Sri Lanka, during September, the rain falls for 13.5 days and regularly aggregates up to 53mm (2.09") of precipitation. Throughout the year, there are 196.8 rainfall days, and 943mm (37.13") of precipitation is accumulated.Daylight
In September, the average length of the day in Nilaveli is 12h and 10min.On the first day of the month, sunrise is at 05:56 and sunset at 18:13. On the last day of September, in Nilaveli, Sri Lanka, sunrise is at 05:53 and sunset at 17:56 +0530.
Sunshine
In September, the average sunshine in Nilaveli is 10.9h.UV index
February through October, 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 radiation for ordinary individuals.Note: A maximum high UV index of 7 in September translates into the following recommendations:
Beware of overexposure. Fair-skinned individuals risk burning in less than 20 minutes. The Sun's UV radiation is most intense from 10 a.m. to 4 p.m. Try to avoid direct sun exposure during these hours. Always opt for UVA and UVB-resistant sunglasses on radiant days.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot does it get in Nilaveli in September?
What is the least humid month in Nilaveli?
What is the average humidity in September in Nilaveli?
How many days does it rain in September in Nilaveli?
How many hours of daylight does Nilaveli have in September?
When is the sunrise / sunset in September in Nilaveli?
How many hours of sunshine does Nilaveli have in September?
What are the months with the highest UV index in Nilaveli?
What is the UV index reading in September in Nilaveli?
Average temperature in September
Nilaveli, Sri Lanka
- Average high temperature in September: 33.9°C
The warmest month (with the highest average high temperature) is April (34.9°C).
The months with the lowest average high temperature are January and December (29.3°C).
- Average low temperature in September: 24.1°C
The month with the highest average low temperature is June (24.8°C).
The coldest months (with the lowest average low temperature) are January and February (20°C).
Average pressure in September
Nilaveli, Sri Lanka
- Average pressure in September: 1008.8mbar
The month with the highest atmospheric pressure is January (1012mbar).
The month with the lowest atmospheric pressure is June (1007.5mbar).
Average wind speed in September
Nilaveli, Sri Lanka
- Average wind speed in September: 18.7km/h
The windiest month (with the highest average wind speed) is June (23.8km/h).
The calmest month (with the lowest average wind speed) is April (7.1km/h).
Average humidity in September
Nilaveli, Sri Lanka
- Average humidity in September: 67%
The month with the highest relative humidity is December (84%).
The months with the lowest relative humidity are June, July, August and September (67%).
Average rainfall in September
Nilaveli, Sri Lanka
- Average rainfall in September: 53mm
The wettest month (with the highest rainfall) is October (214mm).
The driest month (with the least rainfall) is June (15mm).
Average rainfall days in September
Nilaveli, Sri Lanka
- Average rainfall days in September: 13.5 days
The month with the highest number of rainy days is November (24.1 days).
The month with the least rainy days is June (7.8 days).
Average daylight in September /
Average sunshine in September
Nilaveli, Sri Lanka
- Average daylight in September: 12h and 1min
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: 10h and 5min
The month with the most sunshine is June (Average sunshine: 11h and 18min).
The month with the least sunshine is December (Average sunshine: 4h and 54min).
Average sunshine days in September
Nilaveli, Sri Lanka
- Average sunshine days in September: 13.3 days
The month with the most sunshine days is July (16 days).
The month with the least sunshine days is November (4.2 days).
Average UV index in September
Nilaveli, Sri Lanka
- Average UV index in September: 7
The months with the highest UV index are February, March, April, May, June, July, August, September and October (UV index 7).
The months with the lowest UV index are January, November and December (UV index 6).
Average cloud cover in September
Nilaveli, Sri Lanka
- Average cloud cover in September: 30
The month with the most cloud cover is December (Cloud cover 56).
The month with the least cloud cover is May (Cloud cover 26).
Average visibility in September
Nilaveli, Sri Lanka
- Average visibility in September: 10km
The months with the highest visibility are May, June, July, August and September (10km).
The months with the lowest visibility are January and December (7km).
