Most people believe the summer is hot and the winter is cold because the Earth is closer to the sun in summer and farther away in winter.
That’s just not true!
The Earth is closest to the sun in January! If it’s a matter of how close we are to the sun then January should be the hottest month and it’s not.
So what’s going on?
The temperature of Earth has to do with the tilt of its axis; not how close or far it is from the sun. The sun’s rays shine at a steep angle in the summer. Because of this, the light is very focused and a lot of energy hits one spot at a time. In the winter, the sun’s rays hit Earth at less of an angle. With the light spread over a greater distance, there just isn’t enough focused energy to make it very hot.
Another thing at work in keeping summer hot and winter cold is that the days are longer in the summer. This means there’s not only focused light reaching Earth, but plenty of it! In winter, when the days are shorter, there just isn’t enough daylight to heat things up.
Try It Yourself:
Take a flashlight into a dark room.
Shine the flashlight at a steep angle and see how strong the beam is on that spot.
Shine the flashlight at less of an angle and see how strong the beam is on that spot.
(Not sure what a steep angle is versus a shallow angle? If the floor is the 0 degrees and the ceiling is 90 degrees, a steep angle would be when the flashlight is shining down from about shoulder height. A shallow angle would be when the flashlight is shining from around your knee. Give it a try and see for yourself.)
