Year’s fastest sunsets happen around equinoxes

View at EarthSky Community Photos. | Kris Hazelbaker captured this image in Belize on March 4, 2025, and wrote: “We went on a sunset sail, it did not disappoint. It was peaceful and beautiful, with gulls following us, and a beautiful display of bright colors, clouds, sun rays, the ocean.” Thank you, Kris!

Year’s fastest sunsets and sunrises

The March equinox happens at 9:01 UTC on March 20, 2025 (4:01 a.m. CDT). And here’s a little-known equinox phenomenon: the sun sets faster around the time of an equinox. The fastest sunsets (and sunrises) occur at or near the equinoxes. On the other hand, the slowest sunsets (and sunrises) occur at or near the solstices. It’s true whether you live in the Northern or Southern Hemisphere.

And, by the way, when we say sunset here, we’re talking about the actual number of minutes it takes for the body of the sun to sink below the western horizon.

So, why does the sun set so quickly around the equinoxes? It’s because, at every equinox, the sun rises due east and sets due west. That means – on the day of an equinox – the setting sun hits the horizon at its steepest possible angle.

EarthSky’s Raúl Cortés caught the March equinox sun at sunrise. Thanks, Raúl! See more of Raúl’s photos here.

Year’s slowest sunsets and sunrises

Meanwhile, at a solstice, the sun is setting farthest north or farthest south of due west. And, the farther the sun sets from due west along the horizon, the shallower the angle of the setting sun. So that means a longer duration for sunset at the solstices.

Also, the sunset duration varies by latitude. Farther north or south on the Earth’s globe, the duration of sunset lasts longer. So, closer to the equator, the duration is shorter. But let’s just consider one latitude, 40 degrees north, the latitude of Denver or Philadelphia in the United States; parts of Spain; and Beijing, China.

At that latitude, on the day of equinox, the sun sets in about 2 3/4 minutes.

On the other hand, the solstice sun sets in roughly 3 1/4 minutes at 40 degrees latitude.

The equinox is an event that takes place in Earth’s orbit around the sun. Image via National Weather Service/ weather.gov.

View at EarthSky Community Photos. | Jim Grant captured this image in San Diego, California, on January 11, 2025, and wrote: “Smoke particulates had been slowly drifting to San Diego from the fires in Los Angeles. The night before the sun was almost obscured, but winds this day blew a lot of heavy smoke away from the coastline. As the sun started setting I positioned my self to align the sun with the end of the Ocean Beach pier. A combination of layered smoke, clouds and inversion helped create one of the most unique sunsets I have captured in 30 years. And with a green flash.” Thank you, Jim!

Bottom line: The fastest sunsets of the year are happening now, around the time of the March equinox.

March equinox 2025: Everything you need to know

Are day and night equal on the equinox?

Help support EarthSky! Visit the EarthSky store for to see the great selection of educational tools and team gear we have to offer.

The post Year’s fastest sunsets happen around equinoxes first appeared on EarthSky.

from EarthSky https://ift.tt/Ep7K2ij

View at EarthSky Community Photos. | Kris Hazelbaker captured this image in Belize on March 4, 2025, and wrote: “We went on a sunset sail, it did not disappoint. It was peaceful and beautiful, with gulls following us, and a beautiful display of bright colors, clouds, sun rays, the ocean.” Thank you, Kris!

Year’s fastest sunsets and sunrises

The March equinox happens at 9:01 UTC on March 20, 2025 (4:01 a.m. CDT). And here’s a little-known equinox phenomenon: the sun sets faster around the time of an equinox. The fastest sunsets (and sunrises) occur at or near the equinoxes. On the other hand, the slowest sunsets (and sunrises) occur at or near the solstices. It’s true whether you live in the Northern or Southern Hemisphere.

And, by the way, when we say sunset here, we’re talking about the actual number of minutes it takes for the body of the sun to sink below the western horizon.

So, why does the sun set so quickly around the equinoxes? It’s because, at every equinox, the sun rises due east and sets due west. That means – on the day of an equinox – the setting sun hits the horizon at its steepest possible angle.

EarthSky’s Raúl Cortés caught the March equinox sun at sunrise. Thanks, Raúl! See more of Raúl’s photos here.

Year’s slowest sunsets and sunrises

Meanwhile, at a solstice, the sun is setting farthest north or farthest south of due west. And, the farther the sun sets from due west along the horizon, the shallower the angle of the setting sun. So that means a longer duration for sunset at the solstices.

Also, the sunset duration varies by latitude. Farther north or south on the Earth’s globe, the duration of sunset lasts longer. So, closer to the equator, the duration is shorter. But let’s just consider one latitude, 40 degrees north, the latitude of Denver or Philadelphia in the United States; parts of Spain; and Beijing, China.

At that latitude, on the day of equinox, the sun sets in about 2 3/4 minutes.

On the other hand, the solstice sun sets in roughly 3 1/4 minutes at 40 degrees latitude.

The equinox is an event that takes place in Earth’s orbit around the sun. Image via National Weather Service/ weather.gov.

View at EarthSky Community Photos. | Jim Grant captured this image in San Diego, California, on January 11, 2025, and wrote: “Smoke particulates had been slowly drifting to San Diego from the fires in Los Angeles. The night before the sun was almost obscured, but winds this day blew a lot of heavy smoke away from the coastline. As the sun started setting I positioned my self to align the sun with the end of the Ocean Beach pier. A combination of layered smoke, clouds and inversion helped create one of the most unique sunsets I have captured in 30 years. And with a green flash.” Thank you, Jim!

Bottom line: The fastest sunsets of the year are happening now, around the time of the March equinox.

March equinox 2025: Everything you need to know

Are day and night equal on the equinox?

Help support EarthSky! Visit the EarthSky store for to see the great selection of educational tools and team gear we have to offer.

The post Year’s fastest sunsets happen around equinoxes first appeared on EarthSky.

from EarthSky https://ift.tt/Ep7K2ij