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
The arrival of September brings an average high-temperature of a still warm 29.1°C (84.4°F), nearly identical to August's 28.9°C (84°F). Udahamulla records a consistent average nighttime temperature of 24.9°C (76.8°F) in September, slightly lower than the daytime high.Heat index
For September, the heat index is estimated at a torrid 35°C (95°F). Undertake additional safety actions, risk of heat cramps and heat exhaustion is significant. Persistent activity may induce heatstroke.Bear in mind that the heat index values are determined for shaded areas and light breezes. Heat index values can rise by 15 Fahrenheit (8 Celsius) degrees when in direct sunlight.
Note: The heat index, also known as 'felt air temperature' or 'real feel', joins air temperature with relative humidity to produce a temperature perception for humans. This effect tends to be personal, with the weather perception differing among individuals due to variations in body mass, height, and exertion. Considering the impact of direct sunlight, it's possible for the heat index to surge by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for children. Young ones often ignore the need to take a break and drink fluids. Thirst is a late-stage symptom of dehydration - hence, maintaining hydration, particularly during extended physical activities, is crucial.
The physiological response of the human body to excess warmth is to perspire, thereby cooling itself through sweat evaporation. In the presence of abundant moisture in the atmosphere, the cooling process through evaporation is hindered, causing the body to feel excessively warm. Should the body fail to balance its heat gain, the escalating temperature poses health challenges.
Humidity
In September, the average relative humidity is 81%.Rainfall
In Udahamulla, during September, the rain falls for 26.9 days and regularly aggregates up to 206mm (8.11") of precipitation. Throughout the year, there are 289.4 rainfall days, and 2262mm (89.06") of precipitation is accumulated.Daylight
In Udahamulla, 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
In September, the average sunshine is 7.4h.UV index
The months with the highest UV index are January through April, July, September, November and December, with an average maximum UV index of 7. A UV Index estimate of 6 to 7 represents a high health risk from exposure to the Sun's UV rays for average individuals.Note: The maximum daily UV index of 7 in September interprets into the following recommendations:
Persist in precautions and follow sun safety policies. Keeping sunburn at bay is imperative. UV radiation from the sun is at its strongest between 10 a.m. and 4 p.m. Try to limit direct exposure during these hours. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is it hot during September?
What is the average humidity in September?
How much does it rain in September?
How many hours of daylight does Udahamulla have in September?
When are sunrise and sunset in September?
How long on average sun shines in September?
When is the highest UV index?
How high is the UV index in September?
Average temperature in September
Udahamulla, 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
Udahamulla, 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
Udahamulla, 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
Udahamulla, 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
Udahamulla, 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
Udahamulla, 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
Udahamulla, 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: 7h and 2min
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
Udahamulla, 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
Udahamulla, 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
Udahamulla, 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
Udahamulla, 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).
