The polar night is a phenomenon above the Arctic circle that means the sun does not rise above the horizon for an amount of time depending on how near the north pole the place is. In Rovaniemi the polar night, or kaamos as the Finns call it, really do not exist because the sun rises around Christmas time for a couple of hours during the day time. But still people use to call the time around Christmas and New Year the kaamos time. As my friends heard I will stay in Lapland during winter time they asked me how I would cope with the kaamos. After I experienced my first kaamos winter I really have to say, it was no problem at all. On the opposite, I found the kaamos quite exciting with the blue shine all day long, only with an exception of a couple of hours of light yellow sun shine in the middle of the day. You get the feeling of real arctic moments then. It is an relaxing feeling as you are surrounded of this blue atmosphere. It the weather is really cold, as it usually is at that time of the year, the blue light turns out to be even somewhat deeper.
The changes from summer lights to winter kaamos and on the other hand from kaamos to light again happen faster up in the north of Finland than in the south. The fact is that on March 20th and September 22th day and night are the same length in both south and north of Finland. Still in Lapland there are these periods of kaamos and the Midnight sun in the summer, when the sun does not set in the night at all for a period of time. The length of the time of the Midnight sun is depending on how near the north pole the place is; just the same as the fact about polar nights. In Rovaniemi region the Midnight sun period lasts from June 6th to July 6th.
These two pictures are from the polar night.
This picture on the other hand is taken around midnight during the period of Midnight sun in Rovaniemi. It is amazing when you can stay outdoor all night and you have no problem to see in front of you because the sun is shining all the time. It is a well known fact that the Lapish people take advantage of these light summer nights and they do not sleep very many hours per night. During the winter and kaamos time they on the other hand sleep more hours.