The midnight sun is a natural
phenomenon occurring in summer months at places north of the Arctic Circle and
south of the Antarctic Circle where the sun remains visible at the local
midnight. Around the solstice (June 21 in the north and December 21 in the
south) and given fair weather the sun is visible for the full 24 hours. The
number of days per year with potential midnight sun increases the farther
towards either pole one goes. Although approximately defined by the polar
circles, in practice midnight sun can be seen as much as 90 km outside the
polar circle, as described below, and the exact latitudes of the farthest
reaches of midnight sun depend on topography and vary slightly year-to-year.
This pretty card sent to me by Hilkka
from Finland shows the different poses of the Sun in Northern Finland, namely
in Lapland.
