December weather forecast
Devinuwara, Sri Lanka

December, the first month of the winter in Devinuwara, is still a warm month, with temperature in the range of an average high of 29.9°C (85.8°F) and an average low of 23.8°C (74.8°F).

Temperature

The arrival of December denotes a barely perceptible change in the average high-temperatures to a still warm 29.9°C (85.8°F) from November's 29.8°C (85.6°F). Devinuwara records a steady low-temperature average of 23.8°C (74.8°F) during December.

Heat index

December's average heat index is appraised at a sweltering 37°C (98.6°F). Ensure additional precautions, heat exhaustion and heat cramps may be expected. Heatstroke could occur from sustained activity.
Given the heat index, its values are aligned with shaded sites and gentle winds. If directly exposed to the sun, the heat index could rise by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'felt air temperature', ties air temperature with relative humidity to produce the perceived temperature sensation. This effect is personal, influenced by the individual's physical activity and heat sensitivity, shaped by factors including wind, attire, and metabolic variations. Always consider that direct sunlight exposure might heighten the heat's effects, pushing the heat index up by 15 Fahrenheit (8 Celsius) degrees. Heat index values remain especially vital for babies and toddlers. Young kids are often more at risk than adults as they tend to perspire less. Besides, their skin surface is larger relative to their small bodies, and their increased heat output from their active lifestyle compounds their risk.
The innate cooling system of the human body revolves around perspiration, with the evaporation of sweat being central to this process. Greater relative humidity lessens the rate of evaporation, thus decreasing the body's heat dispersal, which gives rise to a sensation of overheating. When heat gain exceeds the level the body can remove, body temperature begins to rise, and heat-related illnesses and disorders may develop.

Humidity

In December, the average relative humidity is 80%.

Rainfall

In Devinuwara, in December, it is raining for 17.5 days, with typically 48mm (1.89") of accumulated precipitation. Throughout the year, there are 180 rainfall days, and 509mm (20.04") of precipitation is accumulated.

Daylight

With an average of 11h and 48min of daylight, December has the shortest days of the year.
On the first day of the month, sunrise is at 06:02 and sunset at 17:50. On the last day of December, sunrise is at 06:17 and sunset at 18:04 +0530.

Sunshine

With an average of 6.9h of sunshine, December has the least sunshine of the year.

UV index

January through December, with an average maximum UV index of 7, are months with the highest UV index. The months with the lowest UV index are January through December, with an average maximum UV index of 7. A UV Index of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV rays for the ordinary person.
Note: The UV index of 7 during December leads to these advisories:
Implement precautions and maintain sun safety methods. Avoidance of sunburn is demanded. Stay in the shade and limit direct Sun exposure from 10 a.m. to 4 p.m., a time when UV radiation is particularly strong. Remember, however, that shade structures may not provide complete protection. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection.