We just returned from a cruise in which we saw a modest showing of the Aurora last week. It was more static than some of the "shows" that I have seen in videos shot during winter months.
It first appeared about 10:30 on a clear night when cruising from Skagway to Glacier Bay. It reappeared about 2:30 am that night. We were fortunate to see another show 2 nights later when cruising to Sitka. This one appeared about 11:30pm.
Based on the reaction of the crew, it is very unusual to see the Aurora Borealis in the summer. Partly because any cloudiness will prevent viewing and also because of ambient light.