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
Weather in September
Temperature
The dawn of September sees an average high-temperature of a still moderately hot 29.5°C (85.1°F), subtly contrasting with August's 29.2°C (84.6°F). Dehianga experiences a steady low-temperature of 21.1°C (70°F) throughout September.Heat index
For most parts of September, the heat index is estimated at a sweltering 35°C (95°F). Adopt extra safety steps, risk of heat exhaustion and heat cramps is notable. Sustained activity might cause heatstroke.Heat index determinations are made taking into account the shade and light air movements. With direct sunlight, the heat index could increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'feels like', is a single figure representing how weather conditions feel when combining temperature and humidity. The impact of temperature is individual, as people's perception of weather may change based on their body mass, height, and physical activity. When exposed to direct sunlight, it's possible for the heat index to increase by as much as 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for babies and toddlers. In general, children are more at risk than adults because they sweat less. Furthermore, the large skin surface compared to their small bodies and the high heat production due to their actions contribute to this vulnerability.
One of the main methods the human body employs to cool down is by perspiring, as this process allows sweat to evaporate and remove excess heat. A higher relative humidity affects normal body cooling by reducing the evaporation rate, subsequently lowering the rate at which the body cools and increasing the perception of heat. As the body gains more heat than it can dissipate, there's a risk of increasing temperatures and resultant overheating.
Humidity
In September, the average relative humidity is 77%.Rainfall
In September, in Dehianga, Sri Lanka, the rain falls for 23.4 days. Throughout September, 118mm (4.65") of precipitation is accumulated. In Dehianga, 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 in Dehianga is 12h and 10min.On the first day of the month, sunrise is at 06:00 and sunset at 18:15. On the last day of September, sunrise is at 05:55 and sunset at 17:59 +0530.
Sunshine
The average sunshine in September in Dehianga is 10.3h.UV index
January through September, November and December, with an average maximum UV index of 6, are months with the highest UV index. A UV Index estimate of 6 to 7 represents a high health risk from unprotected exposure to Sun's UV rays for ordinary individuals.Note: The UV index of 6 during September translates into the following guidance:
Fend off overexposure. Sun protection is vital. The Sun emits the most powerful UV radiation between 10 a.m. and 4 p.m. Try to avoid direct sunlight during this period. Prioritize a wide-brim hat for comprehensive sun defense for your face, neck, eyes, and ears.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is it hot in Dehianga during September?
What is the average humidity in September in Dehianga?
How much does it rain in Dehianga in September?
What is the average length of the day in September in Dehianga?
When is the sunrise / sunset in September in Dehianga?
How long on average sun shines in September in Dehianga?
When is the highest UV index in Dehianga?
What is the UV index reading in September in Dehianga?
Average temperature in September
Dehianga, 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
Dehianga, 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
Dehianga, 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
Dehianga, 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
Dehianga, 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
Dehianga, 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
Dehianga, Sri Lanka
- Average daylight in September: 12h and 1min
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 2min
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
Dehianga, 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
Dehianga, 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
Dehianga, 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
Dehianga, 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).
Dehianga, Sri Lanka
Weather forecast for your location
2. Allow the app to use your location