Auroras Stretch Across Continents as Rare G4 Solar Storm Strikes Earth

A severe G4‑level geomagnetic storm triggered widespread auroras across parts of Europe and the United States on Monday night, following the rapid arrival of a powerful coronal mass ejection (CME) from the Sun.

The US National Oceanic and Atmospheric Administration’s Space Weather Prediction Centre (SWPC) confirmed that the storm reached G4 intensity—its second‑highest category—after a fast‑moving CME associated with an X1.9‑class solar flare struck Earth earlier than expected. The event produced visible auroras far beyond their usual polar range, with sightings reported across Germany, Switzerland, Ukraine, the UK, and as far south as Alabama and northern California in the US.

According to NOAA, the CME travelled from the Sun to Earth in roughly 25 hours, significantly faster than the typical three to four days required for such solar eruptions. The rapid impact caused Earth’s magnetic field to become highly disturbed, enabling charged particles to reach lower latitudes and generate vivid auroral displays.

Meteorological agencies across Europe, including the German Weather Service and Portugal’s IPMA, confirmed aurora sightings and noted that the storm began on the evening of 19 January following the CME’s arrival. In the United States, NOAA advised residents in northern and central states to look for auroras where skies were dark and clear, with colours ranging from green to red and purple.

G4 geomagnetic storms are classified as “severe” due to their potential to disrupt technology. NOAA warned that such events may cause voltage irregularities in power grids, degrade GPS accuracy, interfere with high‑frequency radio communications, and increase drag on satellites in low‑Earth orbit. While no major disruptions were immediately reported, agencies continue to monitor conditions as the storm fluctuates between strong and severe levels.

Experts note that this is one of the most powerful solar storms in more than two decades, with the last comparable event occurring in 2003. The Sun is currently approaching its “solar maximum,” the peak of its 11‑year activity cycle, during which intense solar storms become more likely.

The storm highlights the growing importance of space‑weather monitoring as modern infrastructure—such as satellites, aviation, navigation systems, and power networks—remains vulnerable to geomagnetic disturbances. At the same time, the event offered a rare natural spectacle for millions of observers across mid‑latitude regions who seldom experience auroras.