You need 3 things to enjoy northern lights: Solar activity, clear skies and luck. On our December trip to Tromso we saw a few minutes of aurora borealis. Best chance of spotting is usally around September and March. We chased around the region by using these sources:
- Solar activity and magnetic field:
Many sites use the KP-indicator for aurora intensity.
- Magnetometer: Whenever peaks show up, this might be a good moment to go outside.
- Aurora-service: short-term forecasting of Kp-values
Next to this KP-value you also need to take into account earth magnetic strength. Negative values are what you need.
2. Clear skies:
Clouds ruin the party. It doesn’t even have to rain or snow to be blocked from auroras. So when you’re checking weather forecast, try to get detailed info on cloudiness. Weather fronts are usually passing from NW to E-SE so sometimes there’s less precipitation in the mainland (aim for Skibotn or Kilpisjarvi).
- Norway lights: Great app that boils it down to the essence: ‘Wait’, ‘Try’ and ‘Go’! They advise you for Tromso and some other cities in the North. Not very detailed though if you can drive 1 or 2 hours to the sites with highest potential.
- AccuWeather: they have hour by hour reporting on all details for almost every village.
- YR.no: Local weather forecast but not very trustworthy during night time, we found out.
Even tho you have all the parameters right (or wrong), you can’t 100% rely on this data. Weather is changing rapidly in this region, and if you don’t have Wifi-connection while on the road, you should just be patient (and wait for gaps when it’s cloudy) and pray to the weather gods. We literally drove in a snow blizzard and enjoyed the dancing lights 30 minutes later.