Winter solstice explained

The winter solstice, which marks the beginning of winter and is the shortest day of the year, will happen tonight at 12:30 a.m. 

Starting tomorrow days will gradually become longer, and the weather will get colder. But why is this?

Most of us know that the Earth spins around its own axis while orbitting the sun. Tonight, the Earth's axis (as seen from the north) will point as directly away from the sun as possible. The closer you're located to the North Pole, the shorter your day will be, according to the Washington Post.  

There are fewer warm rays from the sun hitting the planet today, and theoretically, that would mean that today would also be the coldest day of the year. According to USA Today, there is a lag between the shortest day of the year, and the coldest average temperature for most of the United States because the Earth's surface continues to lose more heat than it receives from the sun in the upcoming weeks. This happens because the Earth's axis is tilted, explains ABC News.  

The solstices have fascinated mankind for centuries. Scientists believe that Stonehenge, a prehistoric monument in the UK, was created as an ancient astronomical calendar.  During the summer solstice, usually June 21, the sun rises over the famous heelstone to mark the longest day of the year.