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
Nampamunuwa's transition from August to September introduces an average high-temperature of a still warm 28.8°C (83.8°F), marking an insignificant variation from the 28.6°C (83.5°F). September nights in Nampamunuwa witness a mild cool down to an average low of 25.2°C (77.4°F).Heat index
In September, the average heat index is calculated to be a fiery hot 35°C (95°F). Greater safety measures are needed, risk of heat exhaustion and heat cramps is high. Continuous activity might trigger heatstroke.The metrics for the heat index are tailored for both shady environments and light winds. When exposed to the direct sun, the heat index may augment by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'feels like', is an amalgamation of air temperature and humidity to express the equivalent perceived temperature. A person's impression of weather can be shaped by several aspects, among them metabolic variations, pregnancy, and levels of physical activity. Direct sunlight can potentially raise the heat index by 15 Fahrenheit (8 Celsius) degrees, so it's crucial to consider. Heat index values are essentially critical for children. 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.
To offset high temperatures, the human body releases sweat which, upon evaporation, cools it down. Increased relative humidity slows down evaporation, thereby decreasing the rate of heat removal from the body, culminating in a sensation of overheating. When the body's heat gain surpasses its removal capacity, body temperature starts to climb, leading to potential heat-related ailments.
Humidity
The average relative humidity in September is 82%.Rainfall
In Nampamunuwa, during September, the rain falls for 24.8 days and regularly aggregates up to 250mm (9.84") of precipitation. In Nampamunuwa, during the entire year, the rain falls for 272.8 days and collects up to 2100mm (82.68") of precipitation.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
In September, the average sunshine is 7.3h.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 threat to health from unprotected exposure to Sun's UV rays for ordinary individuals.Note: The UV index of 7 during September translates into the following guidance:
Exercise precautions and adapt sun safety practices. Defence against skin and eye affliction is paramount. Limit your exposure to the sun's UV radiation, which is strongest between 10 a.m. and 4 p.m., and note that parasols or canopies may not provide full sun protection. 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
Is it hot during September?
What is the average humidity in September in Nampamunuwa?
How much does it rain in September?
How many hours of daylight does Nampamunuwa have in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Nampamunuwa have in September?
What is the month with the highest UV index in Nampamunuwa?
What is the UV index reading in September?
Average temperature in September
Nampamunuwa, Sri Lanka
- Average high temperature in September: 28.8°C
The warmest months (with the highest average high temperature) are March and April (31.4°C).
The month with the lowest average high temperature is August (28.6°C).
- Average low temperature in September: 25.2°C
The month with the highest average low temperature is May (26.4°C).
The coldest month (with the lowest average low temperature) is January (23.3°C).
Average pressure in September
Nampamunuwa, Sri Lanka
- Average pressure in September: 1009.7mbar
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
Nampamunuwa, Sri Lanka
- Average wind speed in September: 13.7km/h
The windiest month (with the highest average wind speed) is June (15.9km/h).
The calmest month (with the lowest average wind speed) is March (8km/h).
Average humidity in September
Nampamunuwa, Sri Lanka
- Average humidity in September: 82%
The months with the highest relative humidity are June, July and August (83%).
The month with the lowest relative humidity is January (74%).
Average rainfall in September
Nampamunuwa, Sri Lanka
- Average rainfall in September: 250mm
The wettest month (with the highest rainfall) is June (329mm).
The driest month (with the least rainfall) is January (37mm).
Average rainfall days in September
Nampamunuwa, Sri Lanka
- Average rainfall days in September: 24.8 days
The month with the highest number of rainy days is August (29.8 days).
The month with the least rainy days is January (11.2 days).
Average daylight in September /
Average sunshine in September
Nampamunuwa, 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 12min).
The month with the least sunshine is November (Average sunshine: 6h and 36min).
Average sunshine days in September
Nampamunuwa, Sri Lanka
- Average sunshine days in September: 3.5 days
The month with the most sunshine days is January (18.3 days).
The month with the least sunshine days is July (0.4 days).
Average UV index in September
Nampamunuwa, 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
Nampamunuwa, Sri Lanka
- Average cloud cover in September: 56
The month with the most cloud cover is September (Cloud cover 56).
The month with the least cloud cover is January (Cloud cover 24).
Average visibility in September
Nampamunuwa, Sri Lanka
- Average visibility in September: 9km
The months with the highest visibility are January, February, March, April, November and December (10km).
The months with the lowest visibility are May, June, July, August, September and October (9km).
