The northern lights are expected to be visible across several U.S. states this week, according to the University of Alaska Fairbanks.

On Wednesday and Thursday, the Kp-index, or planetary index, will be at five and six, respectively. The scale goes all the way up to nine, and any occurrence above five is considered a geomagnetic storm.

The aurora borealis could be seen across parts of Washington, Idaho, Vermont, Wyoming, New Hampshire, Montana, North Dakota, South Dakota, Minnesota, Nebraska, Massachusetts, Maryland, Ohio, Wisconsin, Michigan, New York, Maine, according to the university.