December is here, kicking off meteorological winter across the UK. But if you’d rather hold off on the winter woollies until the winter solstice, that means a couple more weeks of patience.
This event signals the Northern Hemisphere’s shortest daylight hours and darkest night, while launching astronomical winter.
What defines the winter solstice and its effects?
The winter solstice occurs when the Sun appears to pause directly above the Tropic of Capricorn, its southernmost annual position, due to Earth’s 23.5-degree axial tilt. This delivers maximum daylight to the Southern Hemisphere while plunging the North into minimal sunlight. The Latin roots – sol (sun) and sistere (stand still) – capture this apparent standstill before the Sun shifts northward toward summer.
When is the winter solstice this year?
In precise terms, it’s a single instant, not the full day and for 2025, that falls at 15:03 GMT on 21 December.
What causes solstice date shifts?
The solstice date varies slightly year to year because Earth’s orbit is about 365.24 days, so the timing slips by roughly six hours annually and is reset by leap years; orbital shape and axial wobble also play smaller roles. As a result, the December solstice typically falls on the 21st or 22nd in the Northern Hemisphere.
Daylight in the UK
Day length on the solstice depends on latitude, with shorter days further north; London sees under eight hours, while locations in northern Scotland have even less. In parts of the Arctic Circle, the Sun does not rise at all around this time, producing continuous darkness.
Is the solstice the beginning of winter?
This depends on how we define the seasons.
Meteorological winter spans 1 December to late February for consistent climate tracking across equal three-month periods. Astronomical winter, however, launches at the solstice and runs to the March equinox, aligning with Earth’s orbital milestones. By this definition, the solstice does the mark the beginning of winter.
