CHARLOTTE, NC (WBTV) - The winter solstice, which occurs on December 21 or 22 each year in the Northern Hemisphere, is the first astronomical day of winter and the shortest day of the year. However, that doesn’t mean it gets dark out the earliest on the winter solstice.
In fact, starting last week, the sun began setting later and later across most of the contiguous U.S., including here in Charlotte, as I’ve stated on the WBTV morning news this week.
You may wonder how days can still be getting shorter through the winter solstice, which occurs on Friday - December 21 this year - if the sun is starting to set later in the day?
That is because the sun also rises later in the mornings through the winter solstice, and the rate at which sunrise times are becoming later is higher than the rate at which sunset times are becoming later.
Looking at Charlotte, for example, the time of sunrise gets pushed back 15 minutes from 7:13 a.m. on December 1 to 7:28 a.m. on December 21. The time of sunset, however, only changes by 4 minutes, going from 5:11 p.m. on December 1 to 5:15 p.m. on December 21.
After the winter solstice, the opposite occurs with the rate at which sunset times become later in the day being higher than the rate at which the sunrise time becomes later in the day. As a result, the overall length of days (available daylight) increases.
During the middle part of January, the sun will start rising earlier in the mornings, allowing the days to become even longer.
The winter solstice happens when the Earth's axis is tilted the farthest away from the sun. This year, that will occur at 5:23 p.m. EST on December 21.