Northern lights in Reykjavík in September
A solid choice — 31% of September nights offer a real viewing window.
The numbers behind it: September nights in Reykjavík average about 8 dark hours, geomagnetic activity reaches local viewing levels on 83% of days, and 38% of nights offer at least one reasonably clear hour after dark.
Neither clouds nor solar activity dominates — September failures are usually bad single-night luck. Several nights in a row is the honest insurance policy.
September also benefits from the equinox effect: around the equinoxes the Earth's magnetic field couples more efficiently with the solar wind (the Russell-McPherron effect), and 30 years of records show measurably more active days than in midwinter.
Numbers come from 1996–2025 Kp records (GFZ Potsdam) and 2015–2024 hourly cloud history for Reykjavík itself — the full method is on the methodology page. Travelling soon? Check tonight's live Reykjavík forecast.
September against the rest of the year
- Jan32% of nights
- Feb30% of nights
- Mar29% of nights
- Apr24% of nights
- Maymidnight sun
- Junmidnight sun
- Julmidnight sun
- Aug16% of nights
- Sep31% of nights
- Oct29% of nights
- Nov31% of nights
- Dec31% of nights
August in Reykjavík · October in Reykjavík · full year overview
September elsewhere under the oval
- Yellowknife 59% of nights
- Fairbanks 36% of nights
- Kiruna 33% of nights
- Lofoten Islands 33% of nights
- Rovaniemi 29% of nights
- Tromsø 28% of nights
- Abisko 22% of nights