We went to Kiruna in northern Sweden in late January. Kiruna is an interesting little mining town and was under about 10 foot of snow which made for a wonderful wintry experience. Actually seeing the Northern Lights is somewhat of hit and miss process. Don't believe the places that 'guarantee' you will see them - as they are as dependent on the rest of the weather and there actually being sufficient solar activity that night to see the Lights. You have to get a little out of Kiruna (just get a taxi to the other side of the ski slope hill at night) to see the Lights, as Kiruna has a surprising amount of light pollution.
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