Meteorological spring starts March 1 each year. This date is used by meteorologists and climatologists to mark the beginning of the spring season. Meteorological spring will last for three months including March, April and May.
Astronomical spring starts later in the month. This year it is on March 20 at 11:33 a.m. The reason for the later date is because this is when the spring equinox takes place. This is also known as the vernal equinox.
This specific date is marked by the sun crossing the equator as the Earth orbits around it. The sun’s angle is 90° to the equator. It will continue to push this 90° line north until summer when it stops at the Tropic of Cancer. The Tropic of Cancer is located at 23.5° N latitude.
The reason you hear about two spring start dates is because one is an exact time during the year vernal/spring equinox, and the other is the date that starts the three months most related to spring.
Meteorologists and climatologists use the quarter system throughout the year to make it easier to record and keep records during each season. The three-month system does not factor in the changing date of each season through the year. It is a simple three months for spring (March, April, May). The same goes for meteorological summer, fall and winter.
Winter: Dec., Jan., Feb.
Spring: March, April, May
Summer: June, July, Aug.
Fall: Sept., Oct., Nov.
Astronomical Season Dates 2022:
Spring starts on March 20 at 11:33 a.m.
Summer starts on June 21 at 5:13 a.m.
Fall starts on Sept. 22 at 9:03 p.m.
Winter starts on Dec. 21 at 3:59 p.m.