Winter solstice: First day of winter, what it means, shortest day of the year

SACRAMENTO, Calif. — The winter solstice, the official start of winter, is Saturday, Dec. 21, 2024. 

For those north of the equator, the solstice marks the shortest day and longest night of the year.

During the winter solstice, the sun will be at its lowest noontime point in the sky for 2024 because it’s when the northern half of the Earth is tilted its farthest away from the sun due to the planet’s axis.

Those south of the equator will simultaneously see the longest day of the year – known as the summer solstice. The Northern Hemisphere will see less than 12 hours of daylight while the southern half of the Earth basks in daylight longer than 12 hours, according to NASA. 

After the solstice, days will gradually become longer, offering a glimmer of hope for those anticipating the return of extended daylight.

The longest day of the year will come during the summer solstice in June.

The winter solstice begins on Saturday, Dec. 21, around 1:20 a.m. Pacific Time, according to TimeandDate.

While it’s often believed the winter solstice is an event covering a whole calendar day, the solstice actually lasts just a moment, the Old Farmer’s Almanac explains.

ABC10 meteorologist Rob Carlmark says the sun will rise in Sacramento at 7:20 a.m. and set at 4:48 p.m. That means 9 hours, 28 minutes and 12 seconds of daylight. We’ll gain three more seconds of daylight on Dec. 22. 

The winter solstice marks the start of the astronomical winter each year between Dec. 21 and Dec. 22.

In meteorology, the official start of the winter season is on Dec. 1, the beginning of the three coldest months of the year in the northern half of the world.

Astronomical seasons are determined by the Earth’s tilt and sun’s alignment over the equator, according to the National Centers for Environmental Information. These seasons are split into summer and winter solstices, and fall and spring equinoxes.

Additionally, the start dates for solstices and equinoxes vary depending on if it’s a leap year.

Meteorological seasons are split into groups of three months based on annual temperature cycles, the NCEI says. These seasons are more closely aligned to our monthly calendar than astronomical seasons.

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