The Sun crosses the equator: Welcome to astronomical spring

The spring equinox occurs today; astronomical spring begins in Prague – Today at 11:37 CET, the spring equinox will occur. This means that day and night will be almost equal in length worldwide. It also marks the beginning of astronomical spring in the northern hemisphere and autumn in the southern hemisphere.

The equinox occurs when the Sun crosses the celestial equator, an imaginary line that divides the sky into two hemispheres. The Sun then moves from south to north relative to Earth’s axis of rotation.

The length of day and night varies slightly depending on latitude and longitude. In Prague, for example, sunrise will be at 6:04 CET and sunset at 18:10 CET, resulting in a day length of 12 hours and six minutes.

The spring equinox is one of four critical points in Earth’s orbit around the Sun. The others are the summer solstice (June 21), autumn equinox (September 23), and winter solstice (December 21).

The seasons are determined by Earth’s tilt of about 23 degrees relative to its orbital plane. This causes different parts of Earth to receive more or less sunlight throughout the year.

Astronomical seasons differ from meteorological seasons based on average temperatures rather than solar positions. Meteorological spring began on March 1 and will end on May 31.