The seasons are caused by the 23.5° tilt of Earth’s axis. One hemisphere points more directly toward the Sun than the other hemisphere. During summer in the Northern Hemisphere, the North Pole is tilted toward the Sun. The Sun's rays strike the Northern Hemisphere more directly. The region gets a lot of sunlight. Winter solstice for the Northern Hemisphere happens on December 21 or 22. The North Pole of Earth's axis points away from the Sun. Light from the Sun is spread out over a larger area. With fewer daylight hours in winter, there is also less time for the Sun to warm the area.