December weather forecast
Unawatuna, Sri Lanka

As the last month of the year, December's weather in Unawatuna maintains a pleasing equilibrium of rain and sunshine. The average wind speed drops to 9.4km/h (5.8mph), providing calm days perfect for coastal fun. Although some reduction in daylight hours occurs, they still linger around 11.8 hours, ensuring extended outdoor activities. Transitioning from November, December carries forward the decreasing rainfall trend. The conclusion of December ushers in a new climatic year, setting the stage for January to take over again with its distinctive weather traits.

Temperature

Unawatuna experiences an average high-temperature of a still warm 28.9°C (84°F) in December, marking an insignificant shift from 29.2°C (84.6°F) in November. An average nighttime temperature of 24.8°C (76.6°F) marks December.

Heat index

Throughout December, the heat index is appraised at a hot 34°C (93.2°F). Incorporate extra safety measures to avoid heat exhaustion and heat cramps. Continuous activity could provoke heatstroke.
Regarding the heat index, one should be aware it's determined by shaded settings and mild winds. Heat index values have the potential to be boosted by 15 Fahrenheit (8 Celsius) degrees due to direct sunlight.
Note: The heat index, also known as 'felt air temperature' or 'real feel', gives a temperature feeling by integrating air temperature and humidity. Elements such as metabolic variations, being pregnant, and physical activity can impact 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 hold particular significance for children. Children often overlook the need for breaks and fluid intake. Thirst is a late-stage sign of dehydration - hence, it is necessary to stay hydrated, especially during extended periods of physical activities.

Humidity

The average relative humidity in December in Unawatuna, Sri Lanka, is 79%.

Rainfall

In Unawatuna, in December, it is raining for 22.1 days, with typically 114mm (4.49") of accumulated precipitation. Throughout the year, there are 286.9 rainfall days, and 1974mm (77.72") of precipitation is accumulated.

Sea temperature

January, February, June through October and December, with an average sea temperature of 28°C (82.4°F), are months with the coldest seawater.
Note: For engaging in water activities including swimming and diving, temperatures from 25°C (77°F) to 29°C (84.2°F) are perceived as perfect, providing pleasure for extended durations.

Daylight

With an average of 11h and 48min of daylight, December has the shortest days of the year.
On the first day of December, sunrise is at 06:04 and sunset at 17:52. On the last day of the month, sunrise is at 06:18 and sunset at 18:05 +0530.

Sunshine

December has the least sunshine of the year in Unawatuna, with an average of 7h of sunshine.

UV index

January through April, June through August, October through December, with an average maximum UV index of 7, are months with the highest UV index in Unawatuna. A UV Index value of 6 to 7 symbolizes a high health hazard from unsafe exposure to UV radiation for ordinary individuals.
Note: In December, a daily maximum UV index of 7 leads to the following instructions:
Apply measures and align with sun safety principles. Safeguarding against skin and eye injury is pivotal. Avoid direct Sun exposure and seek shade from 10 a.m. to 4 p.m., the period of highest UV radiation. Remember, however, that not all shade structures offer full protection. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage. Notice! The reflection of water and sand increases the UV radiation significantly.