The winter solstice arrives, days will start to get longer
Dec 21, 2023, 6:30 AM
Sunset over Seattle's Green Lake (Photo courtesy of City of Seattle)
(Photo courtesy of City of Seattle)
The winter solstice is at 7:27 p.m. Pacific Time on December 21, initiating the start of astronomical winter. Sunrise will be at 7:54 a.m. and sunset at 4:20 p.m., for a total of 8 hours and 25 minutes for the length of the day. When the sun is out, the day also features the longest shadow of the year since the Sun’s angle above the horizon is at its lowest point. The winter solstice also marks the longest night of the year.
The winter solstice is the moment when the Sun is centered over the Tropic of Capricorn in the Southern Hemisphere at 23.5 degrees south thanks to the tilt of the Earth as it rotates around the sun throughout the year.
In contrast for the Southern Hemisphere, the day is their longest period of daylight, just like our summer solstice in mid-June. Also of interest, those above the Arctic Circle will have no daylight at all on the winter solstice, as well several days on either side of the solstice.
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From a weather perspective, the seasons lag the winter and summer solstices since it takes time for the sun to warm the Earth’s surface, ground and water. So our historical coldest month of the year is January even as our daylight hours start to increase. The same goes for July as our warmest month of the year even as our hours of daylight begin to shrink.
The winter solstice has quite a history over the centuries. Early humans tracked the days by observing the Sun as it cast shadows at different times of the year. Historians believe Stonehenge in England was built to keep track of the Sun’s annual progress across the sky. Many countries around the world have celebrated the Solstice over the centuries, including Europe, Scandinavia, Eastern Europe, Iran, Japan, and parts of Eastern Asia, while in the Southern Hemisphere, many celebrate their Summer Solstice.
After December 21, daylight hours will begin to grow longer, at first slowly as a matter of seconds, and then by the spring equinox in March, peaking at around three and half minutes per day. The increase of daylight will then gradually slow, ending on the Summer Solstice in mid-June with just over 16 hours of daylight. As I often joked just after the Winter Solstice when working at the National Weather Service, summer is coming!
Ted Buehner is KIRO Newsradio’s meteorologist
