Thanks, that seems exactly what I was looking for. (Now I have to figure out the best way to get a alert to my phone if my inbox receives such a mail, probably easiest to use a a mailadress just for this case and then treat this emailadress different)

On iOS there’s an app literally called “Aurora”.

It will notify you when you’re in an area with a high Kp (or above a Kp you specify).

One caveat is, that these events cannot be forecasted in the same way as weather on earth can. You usually only have a lead time of 15 - 45 minutes. See also https://www.swpc.noaa.gov/content/aurora-tutorial

Sure. But if I am awake, those 15 minutes are enough to get dressed and go outside.

Yesterday I just would have had to walk to the balkony to see it, but I was busy with some frustrating coding problem instead ..

same, I was awake for the whole night but completely missed it

I had registered for alerts on https://aurorasaurus.org/. But that alert was sent way too late for me (strongest lights were yesterday around 10-11 PM, and the notification was sent 2 AM today). But I was very lucky and just noticed the lights by accident on my way home.