December Solstice 2023: All About First Day Of Astronomical Winter In Northern Hemisphere, And Year's Longest Night

Winter Solstice: The first day of astronomical spring in the Northern Hemisphere, the Winter Solstice can fall anytime from December 20 to 21. This year, it falls at around 8:57 am IST on December 22.

Winter Solstice is also the shortest day and longest night of the year in the Northern Hemisphere, and the longest day and shortest night of the year in the Southern Hemisphere. During the winter solstice, the Northern Hemisphere receives indirect sunlight.

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December Solstice 2023: This year, the December Solstice, also known as Winter Solstice, falls in India on December 22, 2023. For some regions, it falls on December 21. The first day of astronomical spring in the Northern Hemisphere, the Winter Solstice can fall anytime from December 20 to 21. In rare cases, the winter solstice can fall on December 23. The last time the Winter Solstice fell on December 23 was in 1903. Winter Solstice 2023 falls at around 8:57 am IST on December 22. 

Winter Solstice is also the shortest day and longest night of the year in the Northern Hemisphere, and the longest day and shortest night of the year in the Southern Hemisphere. During the winter solstice, the Northern Hemisphere receives indirect sunlight, and the day is shorter than 12 hours, while the Southern Hemisphere receives direct sunlight. It is the beginning of  summer in the Southern Hemisphere. 

The Northern Hemisphere experiences cooler temperatures, while the Southern Hemisphere experiences warmer temperatures. 

During the December Solstice, the Sun is exactly overhead the Tropic of Capricorn in the Southern Hemisphere. This is the southernmost latitude. So, for the Northern Hemisphere, the Sun is located farthest south. The Earth's North pole is facing away from the Sun. 

The word solstice is derived from the Latin word 'solstitium', which means 'the Sun stands still'. 

After being exactly overhead the Tropic of Capricorn, the Sun reverses its direction. As a result, after the Winter Solstice, the days start becoming longer, and the nights shorter in the Northern Hemisphere. This will continue until the spring equinox in the Northern Hemisphere, and autumn equinox in the Southern Hemisphere. 

Earth is closest to the Sun during winter in the Northern Hemisphere, but the tilt of 23.4 degrees in the Earth's axis causes the Northern and Southern Hemispheres to receive different amounts of sunlight, resulting in different seasons. 

A few weeks after the Winter Solstice, Earth reaches perihelion, the point in the planet's orbit closest to the Sun. 

While the December Solstice marks the shortest day of the year in the Northern Hemisphere, and the longest day of the year in the Southern Hemisphere, the earliest sunset in the former and the earliest sunrise in the latter occur a few days before the December Solstice. This is because the true solar noon, which is the point at which the Sun reaches the highest point in one's sky, comes about 10 minutes earlier by the clock than it does at the solstice. 

It is due to the discrepancy between solar time and clock time that the earliest sunset and earliest sunrise are experienced ahead of the December Solstice, in the Northern and Southern Hemispheres, respectively.

Another reason behind the discrepancy is the oblong orbit of Earth around the Sun. Since the rate at which Earth orbits the Sun depends on the distance between the two celestial bodies, and the Earth is located closest to the Sun around the time of the December Solstice, the planet spins faster, resulting in a larger difference between the solar time and closer time, than other times of the year.