The 1 $ question ? Where do Northern Lights mostly occur?
The occurrence of auroras depends on the latitude of the observer. The Northern Lights form an oval band around the magnetic poles of the Earth. At a distance about 2500 km from these poles, the probability for seeing auroras is almost 100 %.
The northern parts of Finland belongs to the maximum auroral zone In Lapland every second night is an auroral night, contrary to Helsinki every 20th. These are statistical rules giving the average extent of auroras. When the Earth's magnetic field is very disturbed, the auroras can spread all over the country .
The best time to see auroras is between 9 p.m. - 1 a.m. local time. The best months are February to March and October-November.
Ruka in South Lapland right at 66 degrees is at the beginning of the most favorable zone and you should have plenty of chances to see this natural wonder !
Be ready to run to the lake or the nearest hill …at 11 pm on every night…with the right gear as colder it is, better it should be !