Spring's start depends on the definition used:
- Astronomical spring begins with the vernal equinox, which in the Northern Hemisphere for 2025 falls on March 20 at 5:01 a.m. EDT. This day marks when the sun sits directly above the Earth's equator and day and night are roughly equal in length.
- Meteorological spring is defined by calendar months as March 1 to May 31, based on annual temperature cycles and average monthly temperatures.
In the Southern Hemisphere, spring starts around September, aligning with their equinox. Thus, depending on context, spring is either considered to start March 1 (meteorological) or March 20 (astronomical) in the Northern Hemisphere.
