Northern lights in Adak, Alaska

The westernmost town in the U.S., Adak's daylight varies the least in Alaska: roughly 16.75 summer hours, 8 winter.

Adak

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Checking tonight's sky…

See Adak sunrise & daylight times →

The next three nights

Geomagnetic activity (Kp) forecast for the selected town's dark hours. Kp runs 0–9; how much a town needs depends on its magnetic latitude. New to this? What the Kp index means, in plain words → Nights tagged “outlook” use NOAA’s 27-day outlook where the 3-day forecast doesn’t reach — whole-day values, so treat them as rougher estimates.

What Adak needs for a show

Whether aurora reaches a town is mostly a matter of magnetic latitude — distance from the magnetic pole, not the geographic one. Adak sits at magnetic latitude 48.8°, which puts it in the Kp 7 band: when the forecast Kp for the dark hours reaches about 7, the oval's southern edge reaches Adak and displays can appear low on the northern horizon. At Kp 9 or better, expect the band overhead at times. The same law draws the band on the homepage globe: the oval's edge at magnetic latitude 69 − 3×Kp.

Magnetic latitude48.8°
Kp needed (horizon show)About 7
Kp for a strong overhead showAbout 9+
Coordinates51.8800°N, 176.6581°W · Southwest

Kp is only one of four ingredients in the live call above: cloud cover over the dark hours, the town's actual darkness window, and moonlight all count too. A Kp 9 night under solid cloud is still a no — which is why the verdict, not the index, leads this page.

Adak’s aurora season

Adak has a real off-season: from about May 21 to Jul 22 (63 nights) the sun never dips 18° below the horizon, so it never gets truly dark and aurora can't be seen even when it's active. Outside that stretch, 302 nights in 2027 get a true-dark window.

Month (2027)True darknessTypical dark window, mid-month
JanuaryEvery night11 hr 38 min
FebruaryEvery night10 hr 12 min
MarchEvery night8 hr 20 min
AprilEvery nightAround the clock
May20 of 31 nightsAround the clock
JuneNo true darkness—
July9 of 31 nights—
AugustEvery nightAround the clock
SeptemberEvery night7 hr 27 min
OctoberEvery night9 hr 36 min
NovemberEvery night11 hr 16 min
DecemberEvery night12 hr 2 min

True darkness = the sun below −18° (end of astronomical twilight), computed with the standard NOAA solar algorithm for Adak’s coordinates. The live call at the top of this page uses tonight's actual window, not these averages.

More Southwest towns tonight