Lesson 5: Long Days and Short Days

Why is there more daylight in the summer days than in the winter days? How does the amount of daylight affect temperature of the area?

The Sun’s light striking Earth’s curved surface at different anglescauses differential heating and temperatures. As Earth orbits, half the planet is always in sunlight and half is always in darkness. During the Northern Hemisphere’s summertime, the North Pole points toward the Sun, resulting in the Northern Hemisphere getting more hours of daylight compared to the Southern Hemisphere, which gets more hours of darkness. In the height of summer in the Northern Hemisphere, the North Pole has 24 hours of sunlight and no darkness at all. As Earth orbits the Sun, the North Pole points away from the Sun in the winter, resulting in the North Pole being entirely in darkness in the wintertime with no daylight hours at all. Other areas in the Northern Hemisphere have longer periods of darkness compared to daylight hours. Longer periods of daylight allow for greater warming from the Sun. Longer periods of darkness create cooler temperatures. Earth’s tilt results in two different things happening on Earth. Each factor impacts how hot it gets at different times of year in different places on the planet. The tilt causes the angle that the Sun’s light hits Earth to be different at different times of year, and that impacts how intense the sunlight is. The tilt also causes the Sun to shine for longer or shorter periods during a day. If the Sun shines longer, it has more time to heat up that area of the planet. Temperatures are affected by the number of hours of sunlight in a location, as well as how direct the sunlight is in that area.

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