Seasons Notes

Reasons for seasons

The tilt of Earth's axis affects sunlight distribution, creating different seasons.

23.5 degrees

Earth’s axis tilt from the vertical

Axis orientation

The axis always points in the same direction during Earth's orbit.

Summer in the Northern Hemisphere

Occurs when the NH is tipped toward the sun, resulting in longer daylight and direct sunlight.

Winter in the Southern Hemisphere

Occurs when the SH is tipped away from the sun, resulting in shorter days and less direct sunlight.

Equatorial regions

Areas near the equator do not experience significant seasonal changes in daylight or sunlight angles.

Summer Solstice

First day of Summer in the NH, occurring on June 20, when the sun is directly overhead at 23.5° N.

Winter Solstice

First day of Winter in the SH, occurring on June 20, with the shortest day of the year.

Fall Equinox

September 22, the first day of Fall in the NH and Spring in the SH, marked by equal day and night.

Vernal Equinox

Another name for the Spring Equinox occurring on September 22, where day and night are equal in length.

Tropic of Capricorn

The parallel at 23.5° S where the sun is directly overhead on December 21.

March Equinox

The time on March 20 when the NH experiences its first day of Spring.