Northern lights in Juneau, Alaska

Alaska's capital gets about 18 hours of June daylight; December days run a little over 6 hours.

Juneau

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Checking tonight's sky…

See Juneau 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 Juneau 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. Juneau sits at magnetic latitude 61.6°, which puts it in the Kp 3 band: when the forecast Kp for the dark hours reaches about 3, the oval's southern edge reaches Juneau and displays can appear low on the northern horizon. At Kp 5 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 latitude61.6°
Kp needed (horizon show)About 3
Kp for a strong overhead showAbout 5+
Coordinates58.3019°N, 134.4197°W · Southeast

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 5 night under solid cloud is still a no — which is why the verdict, not the index, leads this page.

Juneau’s aurora season

Juneau has a real off-season: from about Apr 27 to Aug 15 (111 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, 254 nights in 2027 get a true-dark window.

Month (2027)True darknessTypical dark window, mid-month
JanuaryEvery night11 hr 56 min
FebruaryEvery night10 hr 6 min
MarchEvery night7 hr 40 min
April26 of 30 nights3 hr 42 min
MayNo true darkness—
JuneNo true darkness—
JulyNo true darkness—
August16 of 31 nights—
SeptemberEvery night6 hr 26 min
OctoberEvery night9 hr 19 min
NovemberEvery night11 hr 27 min
DecemberEvery night12 hr 27 min

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

More Southeast towns tonight