The night sky may be illuminated over the next few days in more than a dozen northern US states, courtesy of a natural phenomenon known as the Northern Lights.

National Oceanic and Atmospheric Administration (NOAA) researchers report that the celestial glow should be visible through Wednesday, Aug. 20, in at least 14 states.

Formally known as the aurora borealis, according to the National Weather Service, the colorful night skies are caused by the interaction between Earth’s magnetic field and the Sun’s plasma.

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What is the K-index?

According to the agency, NOAA is predicting a geomagnetic K-index of 5. The index, according to NOAA, indicates how far away from the poles the Northern Lights might be visible.

The K-index (also called Kp) stands for “Planetary Index” and is an indicator of disturbances in the Earth’s magnetic field.

It ranges from 0 to 9, according to NOAA, and a Kp score between 3 and 5 indicates brighter activity.

Using the geomagnetic storm scale, NOAA ranked the expected event as 1 − considered a minor occurrence.

Which states will see Northern Lights this week?

Here’s what states could catch a glimpse of the aurora this week, according to a NOAA map:

Washington

Idaho

Montana

North Dakota

South Dakota

Minnesota

Wisconsin

Michigan

Iowa

New York

Vermont

New Hampshire

Maine

Wyoming

Alaska

Northern Lights photos

Contributing: USA TODAY’s Melina Khan

Natalie Neysa Alund is a senior reporter for USA TODAY. Reach her at nalund@usatoday.com and follow her on X @nataliealund.