On the night of May 10, 2024, people who had never seen an aurora in their lives walked outside and found the sky rippling green, pink and red. NOAA classified that weekend's event as a G5, or extreme, geomagnetic storm - the strongest to reach Earth since 2003. It was not a one-off. The Sun is moving through the most active phase of its roughly 11-year cycle, and that activity is the reason the northern lights keep appearing in skies that almost never see them.
On May 10, 2024, a barrage of solar flares and coronal mass ejections - eruptions that hurl clouds of charged particles and magnetic fields away from the Sun - sent a stream of plasma straight at Earth. When it arrived, NOAA said, it produced the strongest geomagnetic storm in more than two decades. NASA later called the resulting display one of the most remarkable aurora nights on record, visible from latitudes where the lights are almost never seen. For many watching, it was a first.
The lights themselves are a collision. Particles from the Sun follow Earth's magnetic field toward the poles and crash into gases high in the atmosphere. Oxygen glows green about 60 miles up and red higher still; nitrogen adds blue and purple fringes, as NASA's aurora guide explains. The color depends on which gas is struck and how high above the planet the collision happens.
In quiet years, that glow stays inside the auroral oval, a ring around the magnetic poles - Alaska, northern Canada, Iceland, Scandinavia. A severe storm stretches the oval toward the equator. NOAA rates geomagnetic storms on a five-step scale from G1 to G5, and the May storm reached the top of it. That weekend, auroras were reported across the continental United States and Europe, in places that might see them once in a generation.
The engine behind all of this is the solar cycle. Roughly every 11 years, the Sun's magnetic poles flip, and the star swings between calm and stormy. In October 2024, NASA and NOAA announced that the Sun had entered solar maximum, the most active phase of the cycle, and said the stormy period could continue for at least another year. The announcement, from the Solar Cycle Prediction Panel, came after months of rising sunspot counts and a string of strong eruptions.
Cycle 25 has already been busier than predicted. Sunspot counts - the dark, magnetically tangled patches on the solar surface where eruptions begin - have slightly exceeded the international forecast panel's predictions. The cycle has also produced an X9.0-class flare, the most powerful category on the scale.
That matters for the sky because more sunspots mean more eruptions, and more eruptions mean more chances that one of those storms points at Earth. The same activity that worries satellite operators is what pushes the auroral oval south. The same storms also paint the southern sky, where the display is known as the aurora australis.
What comes next
Space weather is not only a light show. The same storms can disturb satellites, radio transmissions, GPS signals and power grids, which is why NASA and NOAA monitor the Sun around the clock. For most people, the practical effect is simpler: more chances to look up. NOAA's 30-minute forecast maps the oval's current reach in near real time.
NOAA's Space Weather Prediction Center posts aurora forecasts and tracks the Kp index, a 0-to-9 measure of geomagnetic activity - the higher the number, the farther from the poles the lights can appear. Viewing is best under dark skies, away from city lights, looking north after about 10 p.m. A reading of 5 or more usually means a geomagnetic storm watch is in effect.
The current maximum will not last forever. Once it passes, solar activity will ebb toward a quieter minimum, and far-southern auroras will fade with it. But with the active phase expected to stretch into 2026, forecasters expect more nights like last May.
Esmé Brooks
October 19, 2026