Northern lights in Sitka, Alaska

On the outer coast, Sitka enjoys about 18 hours of June daylight and around 6.5 hours in December.

Sitka

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Checking tonight's sky…

See Sitka 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 Sitka 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. Sitka sits at magnetic latitude 60.3°, 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 Sitka 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 latitude60.3°
Kp needed (horizon show)About 3
Kp for a strong overhead showAbout 5+
Coordinates57.0531°N, 135.3300°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.

Sitka’s aurora season

Sitka has a real off-season: from about May 1 to Aug 11 (103 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, 262 nights in 2027 get a true-dark window.

Month (2027)True darknessTypical dark window, mid-month
JanuaryEvery night11 hr 52 min
FebruaryEvery night10 hr 8 min
MarchEvery night7 hr 49 min
AprilEvery night4 hr 13 min
MayNo true darkness—
JuneNo true darkness—
JulyNo true darkness—
August20 of 31 nightsAround the clock
SeptemberEvery night6 hr 40 min
OctoberEvery night9 hr 23 min
NovemberEvery night11 hr 24 min
DecemberEvery night12 hr 21 min

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

More Southeast towns tonight