Kaamos

Polar Night (Finnish = kaamos) is the time of the year when the Sun does not rise above the horizon at any point during the day. Kilpisjärvi is now in Polar Night. Although it might seem that this means that the place is pitch dark all the time, this is actually not true.

Close to midday, the Sun may still be below the horizon, however, it does get quite close to it. During this time, the light levels rise to a twilight before sinking back into darkness again.

Midday on 30-Nov-2013 at KAIRA. (Photo: D. McKay-Bukowski)

In fact only within a five or so degrees of the poles will the location remain in total darkness for more than 24 hours. Astronomical twilight begins when the Sun rises above 18 degrees below the horizon.

Despite the midnight sun in Summer and huge spans of twiilight, the sun never rises particularly high and so the incident light and warmth remains marginal... hence the cooler temperatures.