Every September, the changing of the seasons brings more than just cooler nights and falling leaves. It also unlocks a special window in the sky: the September Equinox, a time when auroras often appear brighter, stronger, and further south than usual. This year, from September 21 to 23, skywatchers across parts of the United States and beyond had the chance to witness nature’s most colorful light show.
What Is the September Equinox?
The equinox happens twice a year, in March and September, when the Sun crosses the celestial equator. On these days, daylight and nighttime are nearly equal across the globe. In 2025, the September equinox occurred on September 22 at 12:20 PM UTC. That was early morning in the United States—8:20 AM on the East Coast and 5:20 AM on the West Coast.
For people, the equinox marks the official start of fall in the Northern Hemisphere and spring in the Southern Hemisphere. But for the Earth’s magnetic field, it marks something more: an opportunity for the aurora borealis, or northern lights, to shine more brightly.
Why Are Auroras Stronger at the Equinox?
Scientists have long observed that auroras peak around the equinoxes. This is because Earth’s tilt and magnetic field line up in a way that makes it easier for charged particles from the Sun to slip through. When these particles crash into Earth’s atmosphere, they release energy in the form of dazzling colors green, red, purple, and pink dancing across the night sky.
This natural effect, often called the “Russell-McPherron effect,” helps explain why auroras are more likely during the September and March equinoxes compared to other times of the year.
Where Could You See the Lights?
During the September 21–23 window, auroras were reported in northern U.S. states including Montana, Minnesota, North Dakota, Wisconsin, and Michigan. Some rare sightings even reached further south, with faint auroral glows spotted as far as Texas under the right conditions.
According to NOAA’s Space Weather Prediction Center, minor geomagnetic storms were expected throughout the equinox period. These conditions made it possible for the aurora borealis to be visible not only in Canada and Alaska but also across more of the continental United States.
How to See Auroras in the Future
Catching the northern lights is never guaranteed, but a few tips can increase your chances:
1. Watch space weather forecasts – Websites like NOAA’s SWPC and Aurora Forecast provide real-time updates.
2. Go north and away from city lights – Dark skies are essential. The further north you go, the better your chances.
3. Look around midnight – Auroras are most likely between 10 PM and 2 AM local time.
4. Bring patience – Sometimes auroras appear in waves, with quiet periods in between.
A Reminder of Earth’s Place in the Cosmos
Events like the equinox aurora remind us that we live on a planet connected directly to the Sun’s activity. The same solar storms that cause colorful skies can also affect satellites, GPS, and even power grids. While scientists study these effects for practical reasons, for most of us the aurora is a breathtaking gift of beauty.
From September 21–23, 2025, people had the chance to stand under the night sky and watch as Earth’s magnetic field turned solar energy into shimmering curtains of light. If you missed it this time, don’t worry the next opportunity comes every year, and the skies are always waiting.
Source: NOAA Space Weather Prediction Center, People.com, Chron.com