Our amount of daylight hours depends on our latitude and how Earth orbits the sun. Earth’s axis of rotation is tilted from its orbital plane and always points in the same direction — toward the North Star. As a result, the orientation of Earth’s axis to the sun is always changing throughout the year as we revolve around the sun. Sometimes the axis points toward the sun and other times away from the sun.
As this orientation changes throughout the year, so does the distribution of sunlight on Earth’s surface at any given latitude.
This tilting leads to a variation of solar energy that changes with latitude. This causes a seasonal variation in the intensity of sunlight reaching the surface and the number of hours of daylight.
The variation in intensity results because the angle at which the sun’s rays hit the Earth changes with time of year.
