Today, December 21, is the winter solstice, and what we like to refer to as the first day of winter.
But what does that really mean? Hasn't winter already started? In November and December, we've already seen extreme winter storms, and now there's a storm for the record books in the Southwest: Parts of¬† California recorded 9 feet of snow from Friday to Sunday, and could be looking at 20 feet by the time the storm ends.
So why do we wait so long to declare winter?
The first day of "meteorological winter" is December 1. Meteorologists like to break the year up into three-month chunks, which happen to coincide with the four seasons. Winter, for us, is December, January, and February. But traditionally, the rest of the world declares that winter begins on this, the shortest day of the year.
At 6:38 p.m. ET on December 21, the sun is directly over the Tropic of Capricorn, which is about 23.5 degrees south of the equator. For the Northern Hemisphere, the sun on this day is at the lowest point from the horizon for the entire year. The word "solstice" comes from the Latin word "solstitium," which literally means "the sun is standing."
For places in the Southern Hemisphere like Australia, Chile, Brazil, and southern Africa, it's the longest day of the year, and they're (usually) basking in warm summer weather.
But for us in the Northern Hemisphere, we're trying to get through a brutal winter that doesn't look as if it's going to end anytime soon. Although the days will get longer from now until June, we won't see the temperatures and snow turn the corner until March. That's because temperature tends to lag the amount of sunlight we receive. The lowest temperatures are recorded about a month after the winter solstice, and the highest temperatures about a month after the summer solstice in the third week of June.
This morning, I listened to holiday music and exchanged gifts and cookies with my co-workers. It's no surprise that many of our most important festivals and celebrations fall close to the winter solstice. It's the time when the nights get shorter and the days get longer, and culturally, it symbolizes rebirth. As CNN meteorologist Rob Marciano said, "Today begins a trend of longer days, shorter shadows, and the sun's relative migration back to the Northern Hemisphere."
So there's something to help you get through the rest of this already extreme winter. Summer is just around the corner.