December weather forecast
Kalmunai, Sri Lanka

As the year concludes in Kalmunai, the monsoon season reaches its peak. Despite the year drawing to a close, rainfall continues to dominate with a record 272mm (10.71"), higher than any previous month. However, average temperatures drop marginally diffusing a slight chill into the air. It is advisable to pack a raincoat or umbrella when visiting during December as rainfall is almost a daily occurrence. Thus, the year ends on a wet note with monsoon at its most pronounced.

Temperature

The average high-temperature for December is a still warm 28°C (82.4°F), closely aligning with the temperature of the preceding month. Nighttime temperatures during December report a consistent average of 24.5°C (76.1°F).

Heat index

For most parts of December, the heat index is computed to be a hot 32°C (89.6°F). Enduring exposure and ongoing activity could cause a sense of fatigue and subsequent heat cramps.
The metrics for the heat index are tailored for both shady environments and light winds. Exposure to direct sunlight may make the heat index values climb by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'felt air temperature', melds the effects of warmth and moisture to generate a feeling of heat. This effect is personal, influenced by the individual's physical activity and heat sensitivity, shaped by factors including wind, attire, and metabolic variations. You should know that direct sun exposure can heighten weather effects, potentially elevating the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant 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.

Humidity

December is the most humid month, with an average relative humidity of 81%.

Rainfall

The month with the most rainfall is December, when the rain falls for 25.2 days and typically aggregates up to 272mm (10.71") of precipitation.

Sea temperature

In Kalmunai, Sri Lanka, in December, the average water temperature is 27.9°C (82.2°F).
Note: Swimming, diving, and similar water activities in temperatures ranging from 25°C (77°F) to 29°C (84.2°F) are seen as very agreeable and pleasurable for lengthy periods without discomfort.

Daylight

With an average of 11h and 42min of daylight, December has the shortest days of the year.
On the first day of December, sunrise is at 06:00 and sunset at 17:43. On the last day of the month, sunrise is at 06:14 and sunset at 17:56 +0530.

Sunshine

With an average of 5.4h of sunshine, December has the least sunshine of the year.

UV index

The months with the lowest UV index are November and December, with an average maximum UV index of 6. A UV Index reading of 6 to 7 represents a high health hazard from unprotected exposure to Sun's UV rays for average individuals.
Note: In December, the average maximum UV index of 6 translates into the following recommendations:
Refrain from overexposure. Fair-skinned individuals could burn in under 20 minutes. Make an effort to avoid direct sun exposure between 10 a.m. and 4 p.m., the peak period for UV radiation, and note that objects like parasols or canopies might not offer full sun protection. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly. Caution! Sand and water surfaces escalate the UV intensity from the Sun.