The Earth doesn't sit straight up and down; it tilts on its axis at an angle of about 23.5º . During the summer solstice, the planet reaches the point in its orbit where one of its poles is tilted at its maximum angle directly toward the Sun . In June (June 20–22): The Northern Hemisphere is tilted toward the Sun. In December (December 21–22): The Southern Hemisphere is tilted toward the Sun. 2. The Sun Hits Its Highest Point Because of this tilt, the Sun appears to travel its highest and longest path across the sky during the day. On the solstice, the Sun is directly overhead at noon at the Tropic of Cancer (in the north) or the Tropic of Capricorn (in the south). In fact, the word solstice comes from the Latin words sol (sun) and sistere (to stand still). For a few days before and after the solstice, the Sun's peak height in the sky appears to "stand still" before gradually lower day by day as the planet moves toward autumn. 3. We Experience the Longest Day o...