When is the extreme day and night phenomenon? What season is it now?

When the earth reaches the summer solstice, there will be an extreme day in the Arctic Circle and an extreme night in the Antarctic Circle.

When the earth reaches the winter solstice, there will be an extreme day in the Antarctic circle and an extreme night in the Arctic circle.

The reasons for this phenomenon are:

From summer solstice, the sun shines directly on the Tropic of Cancer. At this time, the noon sun height angle of the Tropic of Cancer and its north reaches the maximum and the southern hemisphere reaches the minimum.

On the winter solstice, the sun shines directly on the Tropic of Capricorn, at which time the sun's height angle at noon on the Tropic of Capricorn and its south reaches the maximum, and all parts of the northern hemisphere reach the minimum.