Spring Has Sprung: All About the Vernal Equinox
The Northern Hemisphere welcomes spring with the vernal equinox, which can occur between March 19th and 21st depending on the year. This marks the official start of spring based on the Earth's position in its orbit around the sun.
Earth's Tilted Journey
As Earth travels around the sun, it's tilted at an angle. This tilt means the sun's warmth and light hit different hemispheres differently throughout the year.
Equal Light, (Almost) Equal Day and Night
During the equinox, the Earth's axis and orbit align, ensuring both hemispheres receive nearly equal amounts of sunlight. The word "equinox" itself comes from Latin words meaning "equal" and "night." On this day, day and night are roughly the same length, although depending on your location, one might be slightly longer than the other.
Spring and Fall Equinoxes
The vernal equinox signals spring in the Northern Hemisphere, while the Southern Hemisphere experiences autumn. The opposite occurs during the fall equinox, which falls between September 21st and 24th.
Solstices: When Days Reach Extremes
Solstices mark the points when the Earth's tilt is most extreme towards or away from the sun, resulting in vast differences in sunlight received by each hemisphere. Days and nights reach their most unequal lengths during solstices.
The summer solstice brings the longest day and shortest night for the Northern Hemisphere, typically occurring between June 20th and 22nd. Conversely, the winter solstice brings the shortest day and longest night, happening between December 20th and 23rd.
Meteorological vs. Astronomical Seasons
There are two ways to define seasons: meteorological and astronomical. Meteorological seasons are based on weather patterns, with spring starting on March 1st, summer on June 1st, fall on September 1st, and winter on December 1st. Astronomical seasons, like the vernal equinox, are based on Earth's movement around the sun.
