Hi, Is it possible to see northern lights in Oulu during first week of October?
Nights will be dark, so in that sense yes, but chances are slim. Being a couple of hundred kilometers south from the Arctic Circle, it woul require a solar strom stronger than usual.
Well, according to the statistics every third night should have northern lights here, too. It does not have to be a particularly strong solar storm - the lights we can see here are in reality usually above Lapland.
There was already a good display here last weekend!
But nevertheless, you'll have a chance but don't count on it. You just have to be lucky (i.e. there should be clear skies and solar wind hitting earth's magnetosphere at that time).