September weather forecast
Kalutara, Sri Lanka

September arrives with marginal changes in temperature and an appreciable dip in rainfall. The highest temperature recorded is 28.8°C (83.8°F). As Kalutara slowly escapes the monsoon season, the humidity levels begin to steadily decrease, leading to a more comfortable atmospheric condition. The amount of sunshine begins to increase, slightly improving outdoor conditions than the preceding months. September signifies the absolute cessation of the monsoon period and the beginning of a drier spell.

Temperature

September's onset records an average high-temperature of a still moderately hot 28.8°C (83.8°F), a near match to August's 28.6°C (83.5°F). Kalutara, in the month of September, notes an average low temperature of 25.2°C (77.4°F), indicating a small decrease from the daytime highs.

Heat index

In September, the average heat index is evaluated at a sweltering 35°C (95°F). Undertake special precautions, the probability of heat exhaustion and heat cramps is high. Prolonged activity may provoke heatstroke.
Regarding the heat index, one should be aware it's determined by shaded settings and mild winds. Heat index values might soar by up to 15 Fahrenheit (8 Celsius) degrees with exposure to direct sunshine.
Note: The heat index, also known as 'feels like' or 'felt air temperature', gives a temperature feeling by integrating air temperature and humidity. Elements such as metabolic variations, pregnancy, and physical exertion can influence one's weather perception. Direct sun rays have a notable impact on perceived temperature, which can raise the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical for babies and toddlers. Young children typically face greater hazards than adults because they do not sweat as much. Their larger skin surface in comparison to their little bodies and the high heat production from their active nature compounds their vulnerability.
In high temperatures, perspiration kicks in, allowing the human body to cool down through the evaporation of sweat. When there is abundant moisture in the air, the body's cooling through the evaporation process becomes less effective, leading to the sensation of overheating. When body temperature rises due to excess heat gain beyond its removal capability, one might experience heat-related disorders.

Humidity

In Kalutara, the average relative humidity in September is 82%.

Rainfall

In September, the rain falls for 26.3 days. Throughout September, 201mm (7.91") of precipitation is accumulated. In Kalutara, during the entire year, the rain falls for 273.8 days and collects up to 2059mm (81.06") of precipitation.

Sea temperature

In Kalutara, Sri Lanka, in September, the average water temperature is 27.8°C (82°F).
Note: Swimming, diving, and other water endeavors at temperatures between 25°C (77°F) and 29°C (84.2°F) are considered enjoyable and satisfying for extended periods without discomfort.

Daylight

In Kalutara, 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 in Kalutara is 7.6h.

UV index

The months with the highest UV index are January through April, July, September through December, with an average maximum UV index of 7. A UV Index value of 6 to 7 symbolizes a high health hazard from exposure to the Sun's UV rays for average individuals.
Note: The maximum daily UV index of 7 in September converts into the following recommendations:
Deflect overexposure. Sun protection is a necessity. Try to minimize direct Sun exposure between 10 a.m. and 4 p.m., the peak period for UV radiation. Also note that objects like parasols or canopies might not provide complete sun protection. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses. Note! The Sun's UV radiation gets intensified with the reflection from sand and water.