PORTLAND, Ore. — The winter solstice will officially arrive at 7:27 p.m. Pacific Time on Thursday making it the shortest day — and the longest night — of 2023 for Portland and the rest of the United States.
In Portland, that means sunrise will arrive at 7:48 a.m. and sunset will happen at 4:30 p.m., according to the National Oceanic and Atmospheric Administration's Solar Calculator, for a total of 8 hours and 42 minutes of daylight.
The days will technically start getting longer after that, with earlier sunrises and later sunsets, although it'll take some time for the difference to become big enough to be noticeable. In fact, Portland's sunsets have already flipped and been getting later for about the past week, but the sunrises are still getting later and won't flip until early January.
The Earth has a 23.5 degree axial tilt, and the winter solstice occurs at the point in the planet's orbit where the tilt lines up to give the northern hemisphere the least amount of direct sunlight, typically on Dec. 21 or 22, while the southern hemisphere receives its greatest annual amount at the same time.
It's the inverse of the summer solstice, when the tilt brings the northern hemisphere closer to the sun and sets up the longest day of each year. This year's summer solstice was at 7:58 a.m. on June 21, according to the National Weather Service, and Portland saw 15 hours and 41 minutes of daylight that day.
The axial tilt is what drives the planet's seasons, with the winter solstice marking the official start of winter and the summer solstice ushering in the the official start of summer.
