December weather forecast
Negombo, Sri Lanka

December concludes the year in Negombo, Sri Lanka, with a further decrease in temperature compared to November. Less rainfall compared to the previous month marks the beginning of the dry season. While there is a discernible decrease in daily sunshine hours, there are still enough daylight hours for sightseeing. A mild surge in wind speed adds a refreshing ambiance to the coastal city. Notably, clear skies dominate this month, and the visibility is high, enthusiastic for the holiday season.

Temperature

The advent of December in Negombo presents an average high-temperature of a warm 29.9°C (85.8°F), maintaining a close correlation with the preceding month. The low-temperature average for Negombo during December stands at 23.7°C (74.7°F).

Heat index

During December, the heat index is computed to be a fiery hot 37°C (98.6°F). Heightened precautions are necessary, heat cramps and heat exhaustion are potential risks. Continuous activity could lead to heatstroke.
In terms of the heat index, values are set with light wind and shade conditions in mind. A direct sunlight exposure may boost the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'apparent temperature', is an amalgamation of air temperature and humidity to express the equivalent perceived temperature. This effect is subjective, differing among individuals based on their physical activity and perception of heat, which can be influenced by factors like wind, clothing, and metabolic variances. Consider that direct sun exposure can intensify the felt heat, adding potentially 15 Fahrenheit (8 Celsius) degrees to the heat index. Heat index values are extremely significant for babies and toddlers. Youths are typically more endangered than adults since they usually sweat less. Their larger skin surface concerning their smaller bodies and higher heat production due to activity further adds to their vulnerability.
The human body has a built-in cooling mechanism through perspiration; evaporating sweat dissipates the excess heat. Greater relative humidity lessens the rate of evaporation, thus decreasing the body's heat dispersal, which gives rise to a sensation of overheating. Heat-related disorders may develop if heat gain in the body overshadows its cooling capacity, leading to elevated temperatures.

Humidity

The average relative humidity in December in Negombo is 79%.

Rainfall

In Negombo, in December, during 20.3 rainfall days, 139mm (5.47") of precipitation is typically accumulated. In Negombo, during the entire year, the rain falls for 265.4 days and collects up to 1744mm (68.66") of precipitation.

Sea temperature

In Negombo, in December, the average water temperature is 28°C (82.4°F).
Note: For swimming, diving, or other water activities, temperatures from 25°C (77°F) to 29°C (84.2°F) provide the most enjoyable experience for extended periods without discomfort.

Daylight

The month with the shortest days is December, with an average of 11h and 42min of daylight.
On the first day of December, sunrise is at 06:07 and sunset at 17:51. On the last day of the month, sunrise is at 06:22 and sunset at 18:05 +0530.

Sunshine

The average sunshine in December in Negombo is 7h.

UV index

January through April, July, September, November and December, with an average maximum UV index of 7, are months with the highest UV index. A UV Index reading of 6 to 7 represents a high health vulnerability from exposure to the Sun's UV radiation for the ordinary person.
Note: The UV index of 7 during December leads to these advisories:
Enforce precautions and stick to sun safety measures. Preservation from skin and eye damage is essential. From 10 a.m. to 4 p.m., when UV radiation is at its strongest, limit direct exposure to the Sun and note that shade structures may not provide full sun protection. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense. Be cautious! Sand and water surfaces make the Sun's UV rays more potent.