When is the earliest sunset of the year? Many folks think it’s on the winter solstice. But the darkest days are actually now—in early December! Bob Berman explains this phenomenon.
To most of us in North America, this is a dark time of year and the sunsets come exceedingly early. It might surprise you to learn that the earliest sunsets come several weeks before the winter solstice, not on the solstice, as many would guess.
This puzzles people, but it’s actually a reliable yearly sequence.
First comes the earliest sunset, in early December.
Then there’s the winter solstice half a month later—on December 21 in the Northern Hemisphere—the day with the fewest minutes of daylight.
Finally, another two weeks later, in early January, we get our murkiest morning—the latest sunrise.
So we’re now slam bang at the low point of afternoon sunshine. And since far more people are awake and aware of things at 4:30 PM than they are at 6 in the morning, in a very real sense you can forget about the solstice and the official “shortest day of the year” in terms of daylight.
The Darkest Time of Year
So far as what most folks actually experience, THIS is the darkest time of the year.
For example, in Boston, the Sun starts setting at 4:11 p.m. on December 5 and won’t start setting later, at 4:12 p.m., until December 13.
Of course, the degree of darkness varies, depending on how far north you live. As for the time the clock reads at sunset—this also depends on how far east or west your home sits, relative to your standard time zone.
For northern latitudes, the earliest sunsets of the year happen around December 7. Think about 40 degrees latitude, so New York City; Philadelphia, Kansas City, Denver, and Reno.
If you live in the southernmost U.S., or a comparable latitude (about 25 or 26 degrees N. latitude), your earliest sunsets are actually in late November.
Drive just an hour east from where you are right now, and the Sun sets ten minutes earlier. That’s because going east around the Earth’s curve makes your western horizon rise up to block the Sun sooner.
Go a mere 35 miles east, and the sun sets five minutes earlier.
In my region, which is the rural Northeastern US, the very earliest sunsets happen for those who indeed live both north AND east—namely, along the upper coast of Maine.
Your Sunset Time?
Test this out yourself! See when your sun starts setting. Try putting in two days ago, and then today, and one week from now!
Why is the earliest sunset well before the winter solstice?
To put it simply, it all reflects the reality that tropical sunsets hardly vary throughout the year, while polar sunsets change wildly through the seasons. If you lived right smack on the equator, like in Quito, Ecuador, your minutes of daylight would never budge throughout the year, not even by one second.
By contrast, our northern friends in Canada and Alaska experience the most radically short days in December.
But wherever you live, before winter eve starts, afternoons will start getting brighter!