Northern lights in Anchorage: tonight’s chance

Between the mountains and the inlet

Anchorage is pressed between the Chugach Mountains to the east and the waters of Cook Inlet to the west and north. The mountains cut off the eastern sky, which is rarely where the aurora is; the problem is the north, where Knik Arm and the lights of the suburbs sit. On a night at Kp 2.4, the aurora rises only a few degrees above that horizon, and from downtown it is easily lost in the orange glow. A few miles of driving changes the picture: up the slopes of the Chugach the lights fall below you, and toward Palmer and Wasilla the sky opens to the north.

Anchorage is still close to the oval in magnetic terms. Its magnetic latitude, 61.1 degrees, is higher than that of any city in the lower 48, and on an active night the oval can sweep right over the city. When that happens, the light pollution matters much less: an overhead corona is bright enough to stand out even from a parking lot.

Maritime weather

Unlike the Interior, Anchorage receives moist air from the Gulf of Alaska, and its winter skies are more often overcast. NASA POWER's averages run from 63% cloud amount in March to 83% in July. A cloudy forecast in town is not always cloudy everywhere: the Mat-Su valleys sometimes clear when the coast stays covered, and the reverse also happens, so the tool lets you check a second town nearby.

Light through the year

In mid-December Anchorage gets 12.7 hours of full darkness, from 6:35 PM to 7:14 AM. By the spring equinox that falls to 7.2 hours, and from May onward the sky never fully darkens. September brings the dark back with mild temperatures, which makes it the comfortable choice for a first try. Many residents first see the aurora on a drive home from somewhere else, which says something about where the dark sky starts. For a comparison with the Interior, see the Fairbanks page; for the rest of the state, the Alaska page.