01
Find a break in the clouds
Compare cloud forecasts at the locations on the map. A high Kp reading means little behind thick cloud.
OUR METHOD
Guidance you can understand.
We show the evidence, even when it does not give a clear answer.
02
Wait for darkness
The Sun’s elevation tells us how dark the sky is. Darkness and aurora activity are separate signals.
03
Understand the activity
The magnetometer provides regional context. Kp describes global activity. Neither confirms an aurora sighting at your viewing spot.
Forecasts are not observations
Cloud cover comes from MET Norway. Aurora activity uses NOAA SWPC. Darkness is calculated from the position of the Sun. Each source has its own timestamp and freshness limit.
Kp describes global geomagnetic activity. Aurora can occur in Tromsø at low Kp values too. We never display Kp as a percentage chance of you seeing the lights.
Aurora potential
Green: good opportunities. Yellow: opportunities. Red: limited. Grey: unknown. Kp below 2 gives yellow, from 2 green, limited by clouds and light. No guarantee of aurora. The ring marks your selected place. Access must be assessed separately.
Now: MET weather and darkness, the latest valid Kp reading (otherwise a covered forecast), with a fresh Kilpisjärvi magnetometer signal as supporting information, without changing the Kp threshold. Activity applies to the region; weather is assessed at each place.
Ahead: MET weather, darkness and Kp forecast for the selected time. No current magnetometer readings are carried forward.
When the evidence is not enough
Stale or missing critical data stops the recommendation. Unknown cloud cover never becomes zero clouds. A place on the map is not a guarantee that roads, parking or access are open.