Winter Solstice 2023: First Day of Winter and Shortest Day of the Year

The darkest day of the year is on Dec. 21, marking the winter solstice for the Northern Hemisphere. Get ready!

The upcoming winter solstice on December 21st may be overshadowed by holiday lights and festive cheer, but it marks the darkest day of the year in the Northern Hemisphere. As more than 6 billion people living north of the equator prepare for this celestial event, it's important to understand the significance of the shortest day and longest night of the year.

On Thursday, December 21st, the winter solstice will occur, signifying the shortest day and longest night of the year for the Northern Hemisphere. Solstices, occurring twice a year, are defined by the sun's path appearing farthest north or south, depending on the location on the planet. Due to the Earth's tilt, the winter solstice happens when the Northern Hemisphere is tilted furthest away from the sun at 10:27 p.m. ET. Conversely, the Southern Hemisphere experiences the most direct sunlight at the same time.

This lack of direct sunlight on December 21st results in the shortest day of the year for the United States and all locations north of the equator, with daylight lasting less than 12 hours. It also marks the start of the astronomical winter season for the Northern Hemisphere.

The National Centers for Environmental Information explains that astronomical seasons are determined by solstices and equinoxes, while meteorological seasons are based on temperature cycles and closely aligned with the monthly civil calendar. Following the winter solstice, each day in the Northern Hemisphere will gradually receive more daylight until the summer solstice on June 20, 2024.

Ancient civilizations have long recognized the significance of solstices, with structures such as Stonehenge and the Torreon in Machu Picchu, Peru, designed to track the sun's path relative to the Earth. This celestial event has been observed and celebrated for thousands of years, and its importance continues to be recognized today.