December weather forecast
Polonnaruwa, Sri Lanka

December in Polonnaruwa sees a conclusion to the heavy rainy season that characterizes the final quarter of the year. The gradual decrease in rainfall signifies a transition towards the weather conditions reminiscent of the start of the year. Despite the dip in temperatures and a decrease in daylight hours, the weather remains warm and humid, much like the succeeding month of January.

Temperature

January and December bring Polonnaruwa's lowest average temperatures, reaching a high of 29.3°C (84.7°F).

Heat index

The average heat index in December is computed to be a torrid 37°C (98.6°F). Use additional protective measures, heat cramps and heat exhaustion are possible outcomes. Continuous activity might lead to heatstroke.
Records show heat index calculations are tailored for shaded regions and mild winds. Direct sunlight can cause a surge in the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'real feel', is a value derived by merging air temperature with the humidity to convey how the climate feels. An individual's perception of weather can be influenced by a variety of factors including metabolic differences, being pregnant, and their degree of physical exertion. Direct sun exposure is noteworthy in its ability to escalate the felt temperature, potentially adding 15 Fahrenheit (8 Celsius) degrees to the heat index. Heat index values are primarily vital for children. Children frequently underestimate the importance of resting and drinking fluids. Thirst is a symptom of advanced dehydration - hence the need to hydrate regularly, especially during protracted physical exercises.
When temperatures rise, the human body turns to perspiration, using the cooling power of evaporating sweat. In circumstances of high air temperature and humidity (high heat index), the body's perspiration is restricted, heightening the feeling of warmth. Overheating and dehydration threats arise when heat gain goes beyond what the body can comfortably shed.

Humidity

With an average relative humidity of 84%, December is the most humid month in Polonnaruwa.

Rainfall

In Polonnaruwa, Sri Lanka, in December, it is raining for 22.9 days, with typically 127mm (5") of accumulated precipitation. Throughout the year, there are 196.8 rainfall days, and 943mm (37.13") of precipitation is accumulated.

Daylight

The month with the shortest days is December, with an average of 11h and 42min of daylight.
On the first day of December in Polonnaruwa, sunrise is at 06:04 and sunset at 17:45. On the last day of the month, sunrise is at 06:18 and sunset at 17:59 +0530.

Sunshine

With an average of 4.9h of sunshine, December has the least sunshine of the year.

UV index

January, November and December, with an average maximum UV index of 6, are months with the lowest UV index. A UV Index estimate of 6 to 7 represents a high health vulnerability from exposure to the Sun's UV rays for average individuals.
Note: In December, the maximum UV index of 6 translates into these guidelines:
Take precautions and adopt sun safety practices. Protection against sunburn is obliged. The Sun's UV radiation is most potent between 10 a.m. and 4 p.m. Try to limit direct exposure to the Sun during this period. Prioritize a wide-brim hat for comprehensive sun defense for your face, neck, eyes, and ears.