Here are the astronomical reasons for the seasons from The Old
Farmer's Almanac. (Remember, astronomy is at the core of any
almanac which is a "calendar of the heavens." First, seasons are
determined by the direction of Earth's tilt in relation to the
Sun and the angle of the Sun's light as it strikes Earth. - At
one end of the axis is the North Pole; at the other, the South
Pole. - The axis is tilted at a 23.5° angle away from the Sun
during winter in the Northern Hemisphere; it's the opposite in
the summer. In one year, Earth revolves completely around the
Sun while rotating on an invisible axis, like a tilted, spinning
top. The Equator's Position The equator is an imaginary line
dividing Earth into the Northern and Southern Hemispheres. On 2
days each year, on or around March 21 and September 23, the Sun
is directly above the equator. Here is how the equator relates
to the seasons: - In the Northern Hemisphere, spring starts on
the March date, which is called the vernal equinox. - Fall
begins on the Septem