It’s March 19th, the first day of spring.
The vernal, or spring equinox will occur at 11:06pm Eastern Daylight Time this evening.
It’s one of the two times in the year that 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 to the website almanac.com, one of the most frequently asked questions is if spring arrives on March 1st or on the equinox and the answer depends your definition of spring.
Astronomically speaking, the first day of spring is marked by the spring equinox, which falls on March 19, 20, or 21. The equinox happens at the exact moment worldwide, although our clock times reflect a different time zone.
Interestingly, due to time zone differences, there hasn’t been a March 21 equinox in mainland U.S. during the entire 21st century. The last time it happened was in 2007 and we won’t see a March 21 equinox again until 2101.
Meteorologically speaking, the official first day of spring is March 1 (and the last is May 31).
Weather scientists divide the year into quarters to make it easier to compare seasonal and monthly statistics from one year to the next. The meteorological seasons are based on annual temperature cycles rather than on the position of Earth in relation to the Sun,
