The sun is directly overhead at 23.5 degrees north latitude on the summer solstice, which occurs around June 21 each year. This is because the Earth's axis of rotation is tilted at an angle of 23.5 degrees, so the sun's path in the sky changes throughout the year. At the summer solstice, the sun is at its highest point in the sky as seen from the Northern Hemisphere, and it shines directly overhead at 23.5 degrees north latitude.