Strong Geomagnetic Storm Sparks Spectacular Aurora Displays on September 2, 2025

A powerful geomagnetic storm struck Earth in the pre-dawn hours of September 2, 2025, igniting brilliant aurora borealis shows far beyond their usual polar confines. Triggered by a long-duration M2.7-class solar flare from Active Region 4199 on August 30, the resulting coronal mass ejection (CME) delivered a G2 (moderate) impact late on September 1, followed by a G3 (strong) storm during the early hours of September 2.

The National Oceanic and Atmospheric Administration’s Space Weather Prediction Center issued a G3 storm watch, forecasting “strong geomagnetic storm conditions” as the bulk of the CME passed. Space weather physicist Dr. Tamitha Skov described the event as a “cannibal CME,” in which a larger, later eruption overtook an earlier one, intensifying the geomagnetic impact.

Unusual Low-Latitude Auroras Thrill Millions

Thanks to the storm’s strength (Kp index reaching 7-8), auroral displays extended well into mid-latitude regions normally too far south to see the lights. In North America, residents across 18 U.S. states-from Montana and North Dakota through the Upper Midwest to New England-reported vivid green and purple curtains dancing overhead. States as far south as Iowa, Illinois, and Pennsylvania also experienced fleeting glows low on the horizon.

In Europe, observers in Scotland, Scandinavia and, under clear skies, parts of England and Wales (including East Anglia and the Midlands) caught rare glimpses of the northern lights. High-latitude locales such as Alaska, Canada, Iceland, and Tasmania in the Southern Hemisphere likewise enjoyed strong auroral activity.

Impact and Viewing Advice

While providing a memorable spectacle for skywatchers, the storm also prompted minor disruptions to radio communications and GPS navigation, as charged particles disturbed Earth’s ionosphere. NOAA warned that radio operators and satellite users could experience signal fades and timing errors during the peak storm interval.

Aurora chasers were urged to monitor real-time alerts and target the prime viewing window between 10 p.m. local time on September 1 and 4 a.m. on September 2. Optimal conditions occur away from light pollution under clear, dark skies. Photographers were advised to use long-exposure settings-ISO 800-1600 with 10-20 second shutter speeds-to capture the full vibrancy of the display.

Continuing Solar Activity

September marks the start of the Northern Hemisphere’s aurora-viewing season, and forecasters expect elevated geomagnetic activity to persist through the solar maximum, now projected to last until at least 2027. NOAA estimates a 75% chance of additional M-class flares in the coming days, suggesting more auroral shows are on the horizon.

With new active sunspot regions rotating into Earth view, space weather experts remain vigilant for further CMEs that could produce even stronger storms. For those who missed this event due to cloud cover or geographic limitations, additional viewing opportunities may arise around the autumnal equinox on September 22, when geomagnetic disturbances typically intensify.