When will I see them, I cannot tell... But they are definitely the most impressive feature (for me) of the wintery Lapland and just take a minute and a look at this video from some days ago! No wonder everyone who comes to Finland wants to see them and it's difficult for them to accept that it does not happen all year round and every night for that matter.
Northern Lights, Lapland, January 2012
I remember December 2009 when we were in Lapland, in the middle of the night, -20 Celsius, I went out looking for the Aurora Borealis and saw something that could slightly resemble Northern Lights (yeah, wishful thinking) but was most likely lights from the neighbouring village (boring!).
We must go back and next time it will be in February, when it's the greatest chance of spotting them. Or of them surprising you, cause they are just amazing, aren't they? Has any of you witnessed such miracle of nature yet?
O.