The Northern Lights may be visible in the U.S. on Tuesday night, according to a forecast by the National Oceanic and Atmospheric Administration’s Space Weather Prediction Center.
Sky-watchers in 11 U.S. states may have a chance to see the aurora borealis on the northern horizon during the night. It comes in the wake of an unexpected G3-rated geomagnetic storm and Kp 7-strength displays on Sunday, Sept. 14 that were seen across northern U.S. states — as far south as Colorado — as well as in Alaska and Canada.
The Kp index — which provides a rough guide to the intensity of aurora displays — is forecast to reach 5 on Tuesday, but it would be wise to be on alert for more unexpected aurora.
According to Spaceweather.com, the “sun is blowing a gale” and Earth is inside a very fast stream of solar wind, the result of a 310,000 miles (500,000 kilometers) wide coronal hole in the sun’s outer atmosphere that’s shaped like a butterfly. This area of open magnetic fields more easily releases charged particles into space.
The real culprit, however, may be the equinox on Sept. 22, which causes favorable seasonal geometry that can mean unpredictable and impressive displays of auroras.
Where The Northern Lights May Be Visible
NOAA’s latest aurora viewlines indicate that aurora displays are a possibility in northern U.S. states and Canada, with 11 U.S. states having a chance after dark on Tuesday, Sept. 14.
U.S. states that may see aurora include (northerly parts of) Alaska, Washington, Idaho, Montana, Wyoming, North Dakota, South Dakota, Minnesota, Wisconsin, Michigan and Maine. Areas far from light pollution are likely to offer the best views.
NOAA’s geomagnetic storm scale, runs from G1 (minor) to G5 (extreme). If a G1 storm results, auroras could be seen in northern skies along the U.S.-Canada border. If it reaches G2, auroras may be seen as far south as New York and Idaho.
Check NOAA’s 30-minute forecast or use the Glendale App for the latest forecasts.
Why Northern Lights Displays Are Spiking
The cause is the Russell-McPherron effect, which sees the magnetic fields of the sun and Earth connect most efficiently for a few weeks either side of equinoxes. That tends to increase the intensity and frequency of geomagnetic storms. The fall equinox is on Thursday, Sept. 22, 2025.
The possibility of displays of the aurora borealis at more southerly latitudes than is typical is also down to an increase in solar activity, which is currently at a 23-year high due to the current solar maximum period. The sun is now thought to be on the wane, having peaked in late 2024, but the best aurora displays often occur in the few years after solar maximum.
Wishing you clear skies and wide eyes.
