Northern lights tonight?
Three things have to line up: darkness, a clear sky, and the sun in a bad mood (a Kp of 3 or more). The app checks the Kp index (from NOAA) and the cloud cover (from Open-Meteo) for the Reykjavík area. This is tonight's read.
Snapshot from 16 Sep 2026, 22:59 UTC. On icebreakerapp.is this refreshes itself when you open it.
Clouded_out. No forecast yet.
Darkness 21:20 to 05:25, about 8.2 hours of it.
- Kp now1.0
- Kp forecast max4.7
- Low cloud79%
- High cloud82%
- Score10/100
How to read it
Kp is the global geomagnetic index, 0 to 9. In Iceland, Kp 2 with a clear sky already shows a faint arc; Kp 4 and up is the wallpaper stuff. Cloud is the usual killer: low cloud hides everything, high cloud dims it.
Where to go
Out of the city light: Grótta lighthouse, Öskjuhlíð, or anywhere ten minutes past the last streetlamp. Face north, give your eyes ten minutes, keep the phone in your pocket.
When
Late August to mid-April. Peak hours are usually 22:00 to 02:00, but a strong show can start at dinner. The app watches the numbers so you don't have to.
Tonight's weather
10°C, wind 1.4 m/s, sunset 19:49. Kp 1.0 — Low activity expected after dark (19:49). Don't get your hopes up.