December brings with it the definitive onset of winter in
Kolkata, with cool yet comfortable temperatures defining the city's weather. Christmas festivities add a cheerful vibe to the city's atmosphere, making it an ideal month for holiday makers. Despite being winter, the weather is generally mild to warm, particularly in comparison to northern Indian cities. The city is typically dry in December with a mere record of 0.67" of rainfall.
Temperature
The arrival of December in Kolkata signals a subtle shift in temperature, down from a hot 86.5°F in
November to a moderately hot 80.6°F. Despite the drastic temperature difference, Kolkata records an average nighttime low of 58.1°F throughout December.
Heat index
The heat index for December is evaluated at 84.2°F. When exposure and activity are sustained, they could induce fatigue, with a chance of heat cramps.
When referencing the heat index, its values are suitable for shady environments and light breezes. Direct sunlight can potentially boost the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', arises from combining readings of air temperature and relative moisture content. The influence of weather is personal, differing among a variety of individuals based on differences in body mass, stature, and the level of physical activity. Being aware that direct sunlight can impact the felt heat might mean an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for children. Juveniles are regularly less conscious of the need to recuperate and rehydrate. Thirst is a tardy symptom of dehydration - hydration, especially during lengthy physical activities, should be maintained.
Humidity
In Kolkata, the average relative humidity in December is 68%.
Rainfall
In Kolkata, in December, it is raining for 0.9 days, with typically 0.67" of accumulated precipitation. Throughout the year, in Kolkata,
India, there are 101.5 rainfall days, and 70.87" of precipitation is accumulated.
Daylight
The month with the shortest days is December, with an average of 10h and 48min of daylight.
On the first day of December, sunrise is at 6:00 am and sunset at 4:51 pm. On the last day of the month, sunrise is at 6:16 am and sunset at 5:02 pm IST.
Sunshine
In December, the average sunshine in Kolkata is 6.6h.
UV index
December is the month with the lowest UV index in Kolkata, with an average maximum UV index of 6. A UV Index estimate of 6 to 7 represents a high health hazard from unsafe exposure to UV radiation for the average person.
Note: The maximum UV index of 6 during December translates into these guidelines:
Take precautions and adopt sun safety practices. Protection against sunburn is obliged. Stay in the shade and limit direct sun exposure between 10 a.m. and 4 p.m., when UV radiation is at its strongest. Remember, however, that not all shade structures provide full sun protection. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun.