Aurora season in Iceland, month by month
Every figure below is computed from real sun-position astronomy for Reykjavík, not a rough seasonal guess.
Darkness, not the Kp index, is the hard gate on seeing the northern lights in Iceland. The table below shows how many dark hours each month gets on average, at two thresholds: civil dusk (any darkness at all, enough for only the brightest displays) and true dark(a properly dark sky). For tonight's actual forecast — live Kp, cloud cover, and moon brightness — see the live aurora forecast.
Average dark hours per night, by month
Computed for the 15th of each month, Reykjavík, 2026.
| Month | Civil-dusk darkness | Properly dark sky |
|---|---|---|
| January | 16h 10m | 14h |
| February | 13h 30m | 11h 40m |
| March | 10h 30m | 8h 40m |
| April | 6h 50m | 4h 10m |
| May | 1h 50m | 0h |
| June | 0h | 0h |
| July | 0h | 0h |
| August | 5h 10m | 0h |
| September | 9h 10m | 7h 10m |
| October | 12h 30m | 10h 30m |
| November | 15h 20m | 13h 20m |
| December | 17h | 14h 50m |
Frequently asked
When exactly does aurora season start and end in Iceland?
There's no astronomical darkness at all — not even faint civil twilight — roughly from 19 May to 23 July (computed for Reykjavík; the exact dates shift by a day or two each year). Outside that window some darkness exists every night, but for a properly dark sky — what you actually want for aurora hunting — the gap is wider, roughly 27 April to 15 August. Aurora season, practically speaking, is outside that wider window.
Why can't I see the aurora in June or July even with a high Kp index?
Because the sky never gets dark. Iceland sits at roughly 64–66°N, close enough to the Arctic Circle that around midsummer the sun doesn't drop far enough below the horizon for real night — the "midnight sun." The aurora can be just as active overhead in June as in January, but it's invisible against a bright sky no matter how strong the geomagnetic storm is.
What's the difference between "some darkness" and "properly dark" for aurora viewing?
Civil twilight darkness (sun more than 6° below the horizon) is enough to see the very brightest aurora displays, but faint or moderate activity gets washed out. Nautical darkness (sun more than 12° below the horizon) is a genuinely dark sky, where even a modest aurora shows up clearly. The table on this page tracks both thresholds — Iceland gets civil-dusk darkness back a few weeks before it gets properly dark skies back.
Which months have the most dark hours for aurora hunting?
December and January, by a wide margin — Reykjavík gets roughly 14–15 hours of properly dark sky a night around the winter solstice, versus zero for weeks around the summer solstice. More dark hours means more chances for a clear break in the clouds, not a higher Kp index.
About this data
Darkness figures are computed directly from sun-position astronomy (the same calculation that gates the live aurora forecast), for Reykjavík — other parts of Iceland vary by a few minutes either way. This is about darkness only; it doesn't account for geomagnetic activity (Kp) or cloud cover, both of which still have to line up on any given night.