Why does AW UK issue alerts during the daytime?
Our alerts are completely automated; they are issued when the disturbance in the Earth’s magnetic field reaches certain thresholds. This, of course, can occur at any time of the day even though the aurora itself can only been seen during darkness.
We choose to still issue alerts during the daytime for a couple of reasons. Firstly, alerts during the daytime give you prior notice that activity is increased and, if such activity continues into the evening, it gives you time to prepare for aurora hunting later on.
Secondly, although the alert service primarily targets the UK, the Crown Dependencies and the Republic of Ireland, we do have subscribers from across the world. Alerts during UK daytime may, in fact, be during the hours of darkness for such subscribers.