JACKSON, Wyo. — Tuesday, March 19, marks the first official day of spring.
The vernal equinox is the astronomical beginning of the spring season in the Northern Hemisphere. According to the Old Farmer’s Almanac, this occurs when the sun crosses the “celestial equator,” an imaginary line in the sky above Earth’s terrestrial equator.
On the equinox, the Northern Hemisphere and Southern Hemisphere receive roughly equal amounts of sunlight. The same day that represents the beginning of spring for the Northern Hemisphere represents the beginning of autumn for the Southern Hemisphere.
“There are only two times of the year when the Earth’s axis is tilted neither toward nor away from the sun, resulting in a ‘nearly’ equal amount of daylight and darkness at all latitudes,” according to the National Weather Service. “The word ‘equinox’ is derived from two Latin words – aequus (equal) and nox (night). At the equator, the sun is directly overhead at noon on these two equinoxes. The ‘nearly’ equal hours of day and night are due to refraction of sunlight or a bending of the light’s rays that causes the sun to appear above the horizon when the actual position of the sun is below the horizon.”
The amount of sunlight each day will increase until the summer solstice, which will fall on June 20.
Local weather has been reflecting this shift toward spring, with abundant sunshine and warmer daytime temperatures. Buckrail meteorologist Alan Smith anticipated this warmer pattern, citing a ridge of high pressure as the cause for the drier weather.
Punxsutawney Phil predicted an early spring, after all.
