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Farmers Almanac
The 2014 Farmers Almanac
Farmers' Almanac

How do the Seasons Change?

How do the Seasons Change?

Yes something’s in the air — fall. This year (2009) fall officially starts on Tuesday, September 22 at 5:19 pm (Eastern). But do you know why we change seasons?

It’s all in the tilt!
While it may seem that the seasons are caused by the earth’s changing distance from the sun, it’s really due to the tilt of the earth’s axis. This tilt—a 23-degree slant-enables the sun to appear above the horizon for different lengths of time at different seasons. The tilt determines whether the sun’s rays strike at a low angle or more directly.

Imagine the earth as spinning top that is tilted to one side. Due to this tilt, the angle of the sun’s rays changes. During the winter in the northern hemisphere, the earth is tilted away from the sun, so the sun isn’t very high in the sky. In the summer, the opposite is true, and due to the direct rays of the sun, the earth heats up more.

Check the sunrises
Ever notice the change in where the sun rises throughout the year? This can also be attributed to this tilt. During the winter, the sun will rise in the southeast. As spring gets closer, the sunrise will move to the north. On the first day of spring, the sun rises directly in the east. During the spring, the sunrise continues to move north and rises in the northeast by the first day of summer. Then, it starts heading south again and rises directly in the east on the first day of fall.

If you’re an early riser, see for yourself on Monday or even Tuesday which way is east by watching the sun rise.

If you notice a hole in the upper left-hand corner of your Farmers' Almanac, don't return it to the store! That hole isn't a defect; it's a part of history. Starting with the first edition of the Farmers' Almanac in 1818, readers used to nail holes into the corners to hang it up in their homes, barns, and outhouses (to provide both reading material and toilet paper). In 1910, the Almanac's publishers began pre-drilling holes in the corners to make it even easier for readers to keep all of that invaluable information (and paper) handy.