December weather forecast
Kalutara, Sri Lanka

December rounds up the year with lesser rains, moderate temperatures, and favourable beach conditions. The highest temperature in December reaches an average of 29.7°C (85.5°F), closing the year on a warm note. With 93mm (3.66") of rainfall spread over 16.5 days, December records the lowest rainfall days of the year. The promising weather conditions heighten tourist activities and contribute to the festive spirit in Kalutara. Being in the dry season, it offers the perfect atmosphere for the year-end celebrations.

Temperature

As November transitions into December, the average high-temperature in Kalutara rests at a still moderately hot 29.7°C (85.5°F), maintaining a close resemblance to the previous month. December generally records an average low-temperature of 24.4°C (75.9°F).

Heat index

During December, the heat index is estimated at a fiery hot 36°C (96.8°F). Take extra precautions, as heat cramps and heat exhaustion are possible. Sustained activity may result in heatstroke.
Note that heat index values are valued for light wind and location in the shade. Direct sunlight exposure may result in a rise of the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'apparent temperature', comes about by integrating the temperature readings with the humidity levels. Factors encompassing physical activity, clothing, and metabolic differences have a role in shaping the individual's impression of temperature. Under direct sun rays, the felt temperature might be heightened, with the heat index increasing by 15 Fahrenheit (8 Celsius) degrees. Heat index values are essentially critical for children. Younglings are generally more in peril than adults due to their reduced perspiration. Coupled with a larger skin surface relative to their tiny bodies and greater heat production because of their activity, they become more at risk.
Evaporation of sweat is the main factor behind the cooling effect of perspiration in the human body. Under conditions of increased relative humidity, the evaporation rate lessens, causing the body to retain more heat than under less humid conditions. Heat absorption that surpasses the body's shedding capability can lead to overheating and varying levels of dehydration.

Humidity

In December, the average relative humidity is 79%.

Rainfall

In Kalutara, in December, during 16.5 rainfall days, 93mm (3.66") of precipitation is typically accumulated. In Kalutara, Sri Lanka, during the entire year, the rain falls for 273.8 days and collects up to 2059mm (81.06") of precipitation.

Sea temperature

In Kalutara, in December, the average water temperature is 28.1°C (82.6°F).
Note: Between the temperatures of 25°C (77°F) and 29°C (84.2°F), water is considered very warm, providing pleasure in water activities without discomfort over lengthy periods.

Daylight

The month with the shortest days is December, with an average of 11h and 48min of daylight.
On the first day of the month, sunrise is at 06:06 and sunset at 17:52. On the last day of December, in Kalutara, sunrise is at 06:20 and sunset at 18:05 +0530.

Sunshine

In December, the average sunshine in Kalutara is 7.1h.

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 unprotected exposure to Sun's UV rays for the ordinary person.
Note: In December, the average maximum UV index of 7 translates into the following recommendations:
Resist extreme sun exposure. Guarding against solar damage is essential. Limit direct sun exposure and seek shade between 10 a.m. and 4 p.m., the time of the most intense UV radiation, noting that shade structures may not provide total sun protection. On days when the sun blazes, arm yourself with sunglasses that block UVA and UVB radiation. Caution! The reflection of sand and water significantly amplifies the Sun's UV radiation.