Northern lights in Reykjavík in September
57%
of 4-night stays in September saw the northern lights at least once, by our estimate. On any one night the chance was 23%. September is a good month in Reykjavík, though December (69%) was better.
How long to stay in September
Chance of at least one good night, by length of stay, Reykjavík in September, 2015–2025. 7 nights got you to about 3 in 4.
In a typical September, the longest run of nights without a single clear, dark hour was 6 nights. A stay shorter than that can fall entirely into one cloudy spell.
Week by week in September (4-night stay)
- 2 Sep – 8 Sep50%
- 9 Sep – 15 Sep50%
- 16 Sep – 22 Sep62%
- 23 Sep – 29 Sep68%
September in Reykjavík, year by year
Good nights in September, each year 2015–2025. The typical September had 7 good nights; the worst, 2021, had 2 and the best, 2019, had 10.
A good night = at least one hour that was dark (sun below −12°), mostly clear (NASA POWER cloud data, calibrated on FMI weather stations) and had a Kp index at or above the Kp 2.3 that Reykjavík needs (GFZ Potsdam). These are estimates, not sightings. How it works
Other destinations in September
Reykjavík ranks 14th of 21 popular aurora destinations for September (4-night stays, 2015–2025).
Yellowknife
94%Churchill
92%Alta
71%Lofoten
69%Kilpisjärvi
67%Abisko
65%Aurora tours in Reykjavík in September
A guide with a car can drive to wherever the clouds break. With cloudy spells of 6 nights in a typical September, that matters here. Booking for your first night leaves the rest of the stay to try again if it's cloudy.
Reykjavík in September: questions
September is a good month in Reykjavík, though December (69%) was better. In 2015–2025, 57% of 4-night stays in September saw the northern lights at least once, and an average September had 7 good nights (clear, dark and with auroras strong enough) out of 30. These are estimates from NASA cloud records and the Kp index, not sightings.
2 nights gave 37%, 4 nights gave 57%, 7 nights gave 76% odds of at least one good night in September (2015–2025). For about 3-in-4 odds, plan 7 nights or more. In a typical September, the longest run of nights without a single clear, dark hour was 6 nights. A stay shorter than that can fall entirely into one cloudy spell.
About 7.4 hours a night with the sun more than 12° below the horizon, which is dark enough for faint auroras. Of those, 1.9 hours a night were mostly clear on average, and 11 nights in an average September had at least one clear, dark hour.
Auroras can appear any time it's dark, but activity usually peaks around midnight, roughly 22:00 to 02:00. With about 7.4 hours of darkness a night in September, start looking as soon as it's dark and stay out past midnight if you can. The live forecast shows tonight's best hour.