Winter solstice 2015 has arrived which means days now get longer. The shortest day of the year – and the first day of winter – occurred in the Northern Hemisphere during the late hours of December 21 and the early hours of December 22, depending on where you live.
The astronomical event also means it was the longest day of the year for those who live south of the equator.
Winter solstice began at 4:48 a.m. UTC on December 22 or 11:48 p.m. ET on December 21, marking the moment when the Northern Hemisphere is pointed at its farthest distance from the sun.
While the solstice marks the shortest day of the year, it also marks the sun’s steady climb toward longer and warmer days of summer.
Regardless of where you live, winter solstice occurs at the same moment around the globe because the Earth is divided into 24 time zones, meaning people observe it at 24 different times of day.
The reason for the season is the Earth’s tilt. Our planet orbits the sun, which is tilted at an average of 23.5 degrees, leaving the Northern and Southern Hemispheres to receive unequal amounts of sunlight, which causes both the solstices and the seasons.
The winter solstice, which occurs in December in the north and during June in the south, marks when half of the globe is tilted away from the sun at its most extreme angle. While the lack of sun exposure makes winter solstice the darkest day of the year, it does not make it the coldest.