Today is the Winter solstice which means the days can only get longer after today. Winter solstice marks the day with the shortest amount of sunlight in a day for the northern hemisphere.
Read below to learn more about Winter solstice.
1. What happens on winter solstice?
The Winter solstice is the moment when the sun’s direct rays are at the most southern point along the Tropic of Capricorn, just south of the equator. The date and time of the solstice change each year and this year it occurred today at 9:28 a.m Mountain Time.
We have a solstice because the Earth is tilted on its axis of rotation by 23.5 degrees and is also the reason for the change of seasons. Each hemisphere receives a different amount of sunlight all year due to the tilt. The sun takes its shortest and lowest path in the Northern Hemisphere which also causes your longest shadow of the year at noon.
As most words in the English language, “solstice” comes from a Latin term. The word comes from the term sol sistere which translates to “sun standing still”. The sun’s southward movement appears to pause on December solstice and we see it rise and set at its most southern points before reversing.
2. How many hours of daylight are there on the winter solstice?
The amount of daylight you’ll see on the solstice depends on your latitude, or distance from the equator.
The more southern states like Florida and Texas will see sunlight for more than 10 hours while northern states see less sunlight under nine hours. Denver is just under the 10 hour mark, seeing a total of 9 hrs and 21 minutes of sunlight.
Alaska sees the least amount of sunlight between 10:58 AM and 2:40 PM. That’s only 3 hrs and 42 minutes of sunlight! The further north you go, the less sunlight there will be with no sunset or sunrise at the 66.5 degree north latitude mark.
3. When are sunrise and sunset?
Latitude and geographic location of your time zone play a role in the exact times of sunrise and sunset.
Most of the country saw sunrise between 7 AM and 8 AM. The majority of Colorado saw sunrise between 7:00 and 7:30 AM while the northwest area saw sunrise between 7:30 and 8:00 AM. Some areas in the more northern part of the United States didn’t see sunrise until after 8:00 AM. The national sunrise time was 7:22 AM.
As for the sunset, the majority of Colorado can wave goodbye to the sun today between 4:30 and 5:00 PM which is the same time for the majority of the country. A small region in the northeast corner of the state will see sunset by 4:30 PM. Some areas such as Texas and Florida are a bit luckier and won’t see sunset until after 5:30 PM. The national sunset average time is 4:50 PM.
There is good news, though. After today, the days will only get longer from here on out!
4. The earliest sunset and latest sunrise don’t occur on the solstice?
While the winter solstice does have the shortest amount of daylight, it is never the day with the latest sunrise and/or the earliest sunset. This is due to the Earth’s tilt and the way the planet orbits the sun in an elliptical pattern (read more).
Most locations see the earliest sunset just two weeks prior to the solstice. The latest sunrise won’t occur until January. Denver saw it’s earliest sunset on December 7th at 4:35 PM and the latest sunrise is on January 4th at 7:21 AM.
5. Why does it get colder after the Winter solstice?
The reason it gets colder after the Winter solstice is due to what is called seasonal lag. The reason for this is due to solar energy amounts leaving the earth vs the amounts hitting the ground. The amount of the energy arriving is less than the amount leaving for a few weeks. In the original article, they used the example of your bank account losing money because you’re making more withdrawals than deposits. Bodies of water take longer to heat up or cool down compared to land, keeping temperatures from rising quickly. Average temperatures won’t begin to see an increase until the Northern Hemisphere sees a gain in solar energy.
The coldest time stretch of the year includes a number of factors including your proximity to water, the current wind direction and amount of snow. Western states usually see their coldest time of year around the time of the solstice. Other areas like New England don’t see their coldest time of year until later in January.
View the original article using maps showing specific locations and times.
Source: Justin Grieser, Washington Post