Fittingly, that day will also feature the most daylight of the year.
On that day, the earth arrives at the point in its orbit where the North Pole is at its maximum tilt − about 23.5 degrees − toward the Sun. When this occurs, the sun is overhead directly hitting the earth’s surface, therefore “more light (and more heat) hit each square centimeter of the ground,” according to National Weather Service.
This all takes place while the earth is at its farthest point from the Sun because the earth’s orbit is not a perfect circle, but rather an ellipse; therefore, one point of the ellipse is closest to the sun and another furthest, according to Space.com.