When Spring Starts Depends on Where You Are
The two main definitions of spring — astronomical and meteorological — can differ by up to three weeks. Astronomical spring begins at the vernal equinox (around March 20th-21st in the Northern Hemisphere), while meteorological spring always starts on March 1st, covering the three calendar months of March, April, and May. Weather services and climatologists prefer the meteorological definition because fixed three-month blocks make it easier to compare seasonal data across years.
In the Southern Hemisphere, the seasons are reversed: spring runs from September to November, with the vernal equinox falling around September 22nd-23rd. Countries like Australia, New Zealand, South Africa, and Argentina experience spring while the Northern Hemisphere enters autumn. Near the equator, the concept of spring is largely irrelevant — tropical regions experience wet and dry seasons rather than the four-season cycle of temperate latitudes.
The first day of astronomical spring in the Northern Hemisphere — the vernal equinox — falls on or around March 20th or 21st each year. In 2026, the spring equinox occurs on March 20th. The exact date and time shift slightly from year to year because the solar year does not align perfectly with the calendar year.
What Is the Vernal Equinox?
The word "equinox" comes from the Latin for "equal night." On the vernal equinox, the sun crosses the celestial equator heading northward, resulting in a day and night of nearly equal length — roughly 12 hours of daylight and 12 hours of darkness at most locations on Earth. After the equinox, days in the Northern Hemisphere grow progressively longer until the summer solstice in June. The vernal equinox marks the moment when the tilt of Earth's axis is perpendicular to the sun, making it the astronomical definition of spring's beginning.
It is worth distinguishing between astronomical spring and meteorological spring. Meteorologists and climatologists define spring as the three-month period of March, April, and May — beginning on March 1st — because it aligns more cleanly with temperature cycles and is easier to use for climate statistics. Astronomical spring, which begins at the equinox, is what most people refer to when they say "the first day of spring."
Cultural Significance and Traditions
The spring equinox has been observed by human cultures for thousands of years. The ancient Persian festival of Nowruz — the Persian New Year — is celebrated at the moment of the vernal equinox and remains one of the oldest continuously observed holidays in the world, celebrated by hundreds of millions of people across Iran, Central Asia, and diaspora communities globally. Stonehenge in England and the Pyramid of Kukulkan in Mexico were both constructed with astronomical alignments that mark the equinoxes.
In the modern world, spring is associated with renewal, growth, and longer days. Spring cleaning — the practice of thoroughly cleaning one's home — is thought to have origins in the Persian Nowruz tradition of "shaking the house," as well as in the practical need to air out homes after a long winter. Easter and Passover both fall in spring and carry themes of liberation and new life. Cherry blossom season, celebrated in Japan as Hanami and increasingly popular in cities worldwide, is one of the most visually iconic markers of spring's arrival.
For more information, see Spring on Wikipedia
