Northern Lights Alert: Rare ‘Equinox Auroras’ Could Light Up Skies Across 14 U.S. States This Weekend

Autumn’s arrival isn’t just about falling leaves and cooler air—this year, the changing season may bring something much more spectacular: one of the best chances in recent memory to see the Northern Lights across wide swaths of the northern United States. With the fall equinox on the horizon and solar activity ramping up, skywatchers are being urged to stay alert: a G1‐rated geomagnetic storm is forecast this Sunday (September 21, 2025), and if conditions align, auroras could be visible in up to 14 U.S. states.

This article explains what is happening, why this timing matters, where the lights might be visible, how to prepare, and what to expect.

The Equinox and Why It Matters

At 2:19 p.m. EDT on Monday, September 22, 2025, the sun will cross the celestial equator heading south. This moment marks the fall equinox in the Northern Hemisphere—the official start of astronomical autumn. On this day, the term “equinox” (Latin for “equal night”) becomes literal: daylight and nighttime are nearly the same length across the globe.

For aurora enthusiasts, this isn’t just a calendar event. The equinox is one of the prime windows for seeing auroral activity, because of Earth’s tilt and its magnetic orientation relative to the sun. The equinox effect leads to:

• Shorter days and longer nights, meaning more hours of darkness in which auroras can be seen.
• A geometry that allows the solar wind’s magnetic field to more efficiently connect with Earth’s magnetosphere.
• More frequent, and sometimes more intense, geomagnetic disturbances as charged particles find “openings” in Earth’s magnetic defenses during this special alignment.

Solar Storm Forecast & What’s Coming This Sunday

Forecasters are currently predicting a G1 geomagnetic storm for Sunday, September 21, 2025. While G1 is considered “minor,” it is still strong enough to push auroral activity further south than is usual, especially under good viewing conditions.

What this means:

• The storm may be powerful enough that people in the northern portions of many U.S. states will have a chance to see auroras.
• If things go well (clear skies, little light pollution, favorable magnetic alignment), the aurora could be even more vivid, possibly with motion or color variations.

The timing is fortuitous: the storm is just before the equinox, when the equinox effect is growing stronger. The extended darkness following the equinox further aids visibility.

How Auroras Happen & The Equinox Effect

To understand why this equinox + G1 storm combination is being treated with excitement, here’s how the physics works:

• The aurora borealis occurs when charged particles—electrons and protons—from the sun collide with gases in Earth’s upper atmosphere (mostly oxygen and nitrogen). These collisions excite the gas molecules, which then emit light as they return to their ground states. The colors depend on which gases are involved and their altitudes—greener glows from oxygen around ~100 km, reds at higher altitudes, purples and blues from nitrogen under certain conditions.
• Scientists have long observed a spike in geomagnetic disturbances around the March and September equinoxes. This is often called the “equinox effect.”
• A more formal description of this is the Russell-McPherron effect (from the 1970s). The idea is: when Earth’s magnetic axis is “side-on” to the sun (as during equinoxes), magnetic field lines in the solar wind more easily reconnect with Earth’s magnetic field. When that reconnect happens, the flow of solar wind energy into Earth’s magnetosphere intensifies. The result is a higher probability of auroral displays—stronger, more frequent, and often more southern than at other times of year.

So: equinox timing + solar wind + geomagnetic storm = good chance for auroras.

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State-by-State Chances: Where You Might See the Lights

Forecasters say up to 14 states could see the aurora this Sunday night, depending heavily on local conditions. Visibility will vary strongly with latitude, local horizon, light pollution, and weather.

Here’s a table showing which states are most likely, what to expect, and what you need for the best view.

State	Region in U.S.	Likelihood of Seeing Aurora	Best Conditions Needed
Minnesota	Upper Midwest	High – especially northern and rural areas	Clear nights, darkness after midnight, low light pollution
Wisconsin	Upper Midwest	High/moderate – especially northern parts	Dark skies, away from city lights; good horizon toward north
North Dakota	Northern Plains	High – frequent predictions during such storms	Cloudless sky, minimal urban glow
Montana	Northwest	High in northern and mountainous zones	Higher elevations, clear skies, minimal manmade light
Michigan	Great Lakes	Good chance, particularly in the Upper Peninsula	Late evening visibility, clear horizons across the lake
Maine	Northeast tip	Good – remote areas likely to see glow or displays	Rural, clear skies, minimal moonlight
New York (northern)	Northeast	Moderate – often only faint arcs or glow on horizon	Away from urban lighting, cold clear air helps
Vermont	New England	Lower/marginal – mostly faint glow if storm strengthens	Dark rural settings, horizon clearance northward
New Hampshire	New England	Lower/marginal – similar to Vermont	Remote viewing, clear skies, early morning hours most promising
Idaho (northern)	Northwest/Mountain West	Moderate – possible in high elevation	Mountain areas away from light pollution, early evening if storm peaks
Wyoming (northern)	Mountain West	Moderate – shadowed by terrain often; isolated better	Elevated terrain, clear skies, cold dry air helps
South Dakota (northern)	Great Plains	Marginal to Moderate – depends on storm strength	Clear skies, open view northward; avoid horizon obstructions
Illinois (northern portions)	Midwest fringe	Less likely but possible if the storm is stronger than forecast	Must have minimal light pollution, dark nights, look horizon north
Idaho or possibly Washington/Alaska edges (if thrown in variation)	Depending on forecasts	Very location-specific – mountainous or forested areas increase odds	Clear cold nights, remote locations, patience

These states represent the “edge zone” of where auroras might be visible. The farther from the magnetic north you are, the more ideal the conditions will need to be for you to see anything meaningful.

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When to Look, What to Bring, and How to Maximize Your Chances

To increase your odds of witnessing the auroras, these timing and practical recommendations will help.

Timing

• Evening hours: Start skywatching just after local sunset. The darker it gets, the better; prime times tend to be between 10 p.m. and 2 a.m., local time, but might shift earlier or later depending on storm timing and latitude.
• Sunday night (Sept. 21): With the equinox on Sept. 22, Sunday evening marks the immediate eve of the magnetic alignment.
• Following nights: While Sunday has the forecasted G1 storm, nights in the week before and after an equinox often have elevated aurora potential, so keep watching.

Conditions & Preparation

Factor	Why It Matters	What You Can Do
Darkness / Light pollution	Artificial light washes out weak auroral displays	Go rural, away from city lights; use “dark-sky” parks if possible
Weather / Cloud cover	Clouds, haze extinguish visibility	Check local forecasts for cloud cover, especially toward northern horizon
Moon phase / Moonlight	A bright moon reduces contrast; weak auroras may vanish under its glow	Be aware of moonrise/moonset; darker moon phases are better
Horizon view	Trees, hills, buildings block view of low aurora on horizon	Choose open landscape with unobstructed view to north or northwest
Gear	Cameras, clothing, comfort help prolong the experience and enable seeing faint colors	Dress warmly; if photographing, use tripod, long exposure settings, wide lens, remote trigger if possible

What to Expect Visually

• In the states nearer the magnetic north, you may see arcs, ripples, even bands of light overhead if conditions are good.
• Further south in the “edge states,” more likely a faint glow, maybe greenish or reddish tinge on the northern horizon. Sometimes motion is slow; colors may be muted.
• Activity may come in bursts: periods of quiet followed by more intense curtains or flickers.

The Science Behind the Forecast & Why Timing Aligns

This event isn’t just a random forecast: several scientific ideas are converging and making this equinox especially promising.

Solar Cycle Status

The sun is currently in Solar Cycle 25, which began around 2019 and is expected to run through roughly 2030. While past predictions varied, solar activity has been stronger than some early estimates. Higher numbers of sunspots, more frequent solar wind streams, and occasional coronal mass ejections (CMEs) are more common, increasing the base level of geomagnetic “noise.”

Coronal Holes & Solar Wind Streams

Coronal holes—regions on the sun where magnetic field lines are open and allow solar wind to stream out more freely—are often the culprits behind sustained periods of elevated geomagnetic activity. When a fast solar wind stream from a coronal hole meets Earth, increased geomagnetic disturbance may follow.

These streams don’t always guarantee strong auroras, but when they align with the equinox (and with Earth’s field oriented favorably), their effects are magnified.

Russell-McPherron Effect

As mentioned, this is a key mechanism: during equinoxes, Earth’s orientation relative to the sun allows the solar wind’s magnetic field (particularly the southward component) to reconnect more efficiently with Earth’s magnetic field, facilitating energy transfer into the upper atmosphere. This helps amplify whatever solar wind conditions exist.

Key Facts & Takeaways (Without Tech Jargon Overload)

Here’s a distilled summary of what you really need to know and remember:

• The fall equinox is Monday, September 22, 2025 at 2:19 p.m. EDT. That’s when the sun crosses the celestial equator heading south—ushering in longer nights and a geometry favorable to auroras.
• NOAA is forecasting a G1-class geomagnetic storm for Sunday, September 21. It’s minor but sufficient for aurora sightings in favorable locations.
• Up to 14 U.S. states are in the visibility zone if conditions are good. The farther north you are, the better chance; farther south means you’ll need near-ideal darkness, clear skies, and strong storm periods.
• The equinox effect (and specifically the Russell-McPherron effect) help explain why auroras are more likely around this time of year: Earth’s magnetic axis is more favorably aligned with solar wind fields, letting more solar particles in.
• Strong colors (reds, purples) are less likely unless the storm intensifies beyond G1. Expect mostly green, perhaps with some red toward higher altitude or farther north.

Possible Risks & Things That Could Hinder the Show

Even with a forecast of G1 and the equinox alignment, there are real reasons why things might not look as dramatic as one hopes.

• Cloud Cover & Weather: Local clouds, moisture, or even haze can entirely block visibility or reduce brightness. Even thin cirrus can wash out faint displays. Always check local weather forecasts.
• Light Pollution: City lights, bright outdoor lighting, street lamps, etc., can swamp faint auroral glows. Being even just a few miles outside a city can make a big difference.
• Moonlight: A bright moon can act like a built‐in light pollution source if it’s up high when auroral faintness is expected. Timing around moonrise/moonset matters.
• Storm Strength Variation: The forecast is for G1, but actual geomagnetic activity may be weaker (or occasionally stronger). It depends on solar wind speed, direction, density, and whether the interplanetary magnetic field (IMF) has a southward component.
• Viewing Geometry & Timing: Even in “good” states, you might only see glow near the horizon, or very patchy arcs, or intermittent flickering. The most intense portions may pass quickly or be overhead only briefly.

Historical Comparisons & What Past Equinoxes Teach Us

Looking back at previous years gives insight into what to expect.

• Past equinox‐periods (both spring and fall) often correlate with elevated auroral sightings in areas that don’t regularly see them.
• There have been events where a G1 storm around an equinox pushed auroras visible far south—though those were under unusually favorable conditions (clear skies, strong solar wind, minimal light interference).
• Photographers often report that colors and motion are more vivid when Earth’s magnetic alignment is favorable, especially in highest latitudes, though subtle displays (green faint curtains) are common at lower latitudes.

Visual Guide: What You Might See Depending on Location

Here’s a rough visual expectation chart depending on latitude / location, assuming the G1 storm reaches its predicted strength and skies are favorable.

Your Latitude / Location	Likely Appearance	What Colors & Forms Might Be Seen
Far Northern States (e.g., northern Minnesota, North Dakota, Montana)	Curtains overhead, possibly dynamic arcs, ripples, some motion and structure	Greens dominant; reds at edges; possibly purples or pinks if very active; shapes more distinct
Mid-Northern States (upper Wisconsin, Michigan, northern New York)	Glow on north horizon or arcs rising overhead for a time; intermittent display	Greens, maybe some red/tint; motion may be slower; structure less dramatic but still impressive
Border States / Edge of Visibility (Illinois northern, Vermont, New Hampshire)	Faint glow, sometimes just low light on horizon; possibly just clouded or washed out	Mostly green or whitish; often dim; possibility of red if conditions are excellent and geomagnetic activity peaks
Dark rural / mountainous zones	If you are in a dark zone, even faint displays can look dramatic; overhead arcs possible	Better contrast, deeper colors; chance to see features normally lost in light pollution

How to Plan & Enjoy the Show

If you decide to try catching this auroral event, here’s a suggested plan of action.

1. Check Updates: Keep watching NOAA’s Space Weather Prediction Center (SWPC) or equivalent real-time aurora forecast tools. The forecast may shift somewhat as solar wind arrival and IMF orientation are monitored.
2. Scout Location in Advance: Pick a site with minimal light pollution, clear northern view. High elevation helps. If possible, know the terrain (hills, trees) so horizon is not blocked.
3. Monitor Local Weather: Just before sunset, check cloud cover forecasts in your area—especially toward the northern horizon. Even thin cloud cover can spoil parts of the view.
4. Time Your Night: Plan to be out a few hours after dusk, and stay out late if possible. Bring chairs or something comfortable. Be ready for late-night cold.
5. Bring the Right Gear:
   • Warm clothes, layers, blankets (nights at this time of year can chill)
   • Camera with manual exposure (if possible), tripod, wide lens, remote trigger or timer
   • Flashlight with red filter (preserves night vision)
   • Snacks, water, something to pass time if waiting
6. Patience & Openness to Surprise: Aurora displays often build gradually. Sometimes faint, then stronger. Sometimes sudden bursts. Being ready and staying alert helps.

The Broader Implications: Science, Culture & Technology

Seeing auroras isn’t just a beautiful spectacle—it also connects with deeper intersections of science and human experience.

• Space Weather Science: Every geomagnetic storm (even minor ones) gives scientists data about how Earth’s magnetosphere responds to solar wind. Better understanding helps in forecasting and preparing for larger events that could affect satellites, communications, navigation systems, etc.
• Technological Awareness: While a G1 storm is unlikely to cause major disruption, cumulative or concurrent effects (especially with the solar cycle increasing activity) mean there is some risk—e.g. radio blackouts, GPS errors, perhaps minor effects in power transmission in extreme cases.
• Cultural & Inspirational Value: For many, auroras generate awe, connect people with nature, inspire art, photography, and curiosity about astronomy. Remote or rural communities may benefit (economically or socially) when skywatchers travel; the event can also raise awareness about light pollution, climate, and our connection to the cosmos.

Expectations Summary: What You Might See This Sunday

Putting everything together, here’s a realistic expectations list for Sunday, September 21:

• A chance of seeing a modest auroral display in many of the 14 target states—stronger toward the north.
• Likely green glow or faint arcs in “edge” states; more dynamic forms (curtains, ripples) possible in northern, rural, high-elevation areas.
• Timing most favorable late evening through early morning (roughly 10 p.m. to 2 a.m.), but earlier or later depending on your location.
• Weather and sky clarity will make or break much of the experience. Even a strong storm can look disappointing under cloudy skies.
• For many people, the show may not be a full dramatic aurora display (like those in high Arctic regions), but even a faint shimmering glow on the horizon ought to be memorable.

Conclusion

This Sunday night offers a special opportunity: the convergence of seasonal alignment (fall equinox), solar activity (forecasted G1 geomagnetic storm), and increasing darkness sets the stage for possible Northern Lights displays across 14 U.S. states. While it won’t be guaranteed—and the spectacle will depend heavily on location, weather, and storm strength—the odds are better than much of the rest of the year.

If you can, prepare, head out to a dark sky, stay late, and keep your eyes on the northern horizon. Even if the display is subtle, it’s a chance to connect with a cosmic dance that few moments in the calendar year bring so clearly. And who knows—this Sunday night might surprise you.

Here’s hoping for clear skies and shimmering lights overhead.