Solstice

An astronomical event occurs twice each year, and it is called a solstice.  What happens is that the Earth's axis is most inclined toward or away from the Sun at that point.  This causes the Sun's position in the sky to reach the most northern or southern extreme. 

The name solstice comes from the Latin words sol and sistere.  Sol means Sun and sistere means to stand still.  The standing still part comes from the movement of the Sun's path north or south as it comes to an apparent stop before reversing direction. 

The solstice occurs every year in June and then again in December.  They are generally referred to as the Summer Solstice and the Winter Solstice. 

During the solstice you will also encounter the longest and shortest days of the year. 

This is such a phenomena that there are cultures that celebrate the appearance  of the solstice each year.