Today is the winter solstice and the first day of winter in the Northern Hemisphere. It’s all due to Earth’s tilt, which ensures that the shortest day of every year falls around December 21.
During the winter solstice the sun hugs closer to the horizon than at any other time during the year, yielding the least amount of daylight annually. On the bright side, the day after the winter solstice marks the beginning of lengthening days leading up to the summer solstice.
“Solstice” is derived from the Latin phrase for “sun stands still.”
The solstices occur twice a year (around December 21 and June 21), because Earth is tilted by an average of 23.5 degrees as it orbits the sun—the same phenomenon that drives the seasons.
During the warmer half of the year in the Northern Hemisphere, the North Pole is tilted toward the sun. The northern winter solstice occurs when the “top” half of Earth is tilted away from the sun at its most extreme angle of the year.
Being the shortest day of the year, the winter solstice is essentially the year’s darkest day, but it’s not the coldest.
Because the oceans are slow to heat and cool, in December they still retain some warmth from summer, delaying the coldest of winter days for another month and a half. Similarly, summer doesn’t hit its heat peak until August, a month or two after the summer solstice.
Throughout history, humans have celebrated the winter solstice, often with an appreciative eye toward the return of summer sunlight. In my family, it has been a long time coming for my oldest boys, known to blogosphere as “Linus” as whenever anyone would comment about it being winter, he would remind them that the solstice had not yet occurred and it was technically not winter.
He has been looking forward to this day for other reasons as his birthday is the 27th, so when it was the 21st, he knew there were only 6 more days until he turned 5. He jumped for joy and danced around his room.
Ahhh, to be young again…