First Day of Spring

Welcome to the First Day of Spring calculator. Find the exact date and time of the vernal equinox — the astronomical start of spring — for any year between 2000 and 2038. This tool includes a live countdown, complete seasonal timeline, multi-year comparison, and in-depth astronomical explanations. It supports both Northern Hemisphere (March equinox) and Southern Hemisphere (September equinox) calculations.

What Is the Vernal Equinox?

The vernal equinox (from Latin vernalis meaning "of spring" and aequinoctium meaning "equal night") is the astronomical moment when the Sun crosses the celestial equator heading northward (in the Northern Hemisphere) or southward (in the Southern Hemisphere). At this instant, day and night are approximately equal in length everywhere on Earth — each lasting about 12 hours.

The vernal equinox marks the beginning of astronomical spring, a time of increasing daylight hours, rising temperatures, and the natural world awakening from winter dormancy. It is one of the four primary astronomical events that define our seasons, along with the summer solstice, autumnal equinox, and winter solstice.

When Is the First Day of Spring?

The first day of spring (vernal equinox) typically falls between March 19–21 (Northern Hemisphere) or September 21–23 (Southern Hemisphere). The exact date varies each year because Earth's orbital period is approximately 365.2422 days — not a perfect 365. This fractional difference, corrected by leap years, causes the equinox to shift by roughly 6 hours each year, then snap back during leap years.

Why the Date Changes

• Orbital fraction: Each year the equinox drifts later by about 5 hours 49 minutes relative to the calendar.
• Leap year correction: Adding February 29 shifts the equinox earlier by about 18 hours, keeping it anchored to March 19–21.
• Planetary perturbations: Gravitational pull from the Moon, Jupiter, and Venus create minor variations of a few minutes.

Astronomical Spring vs. Meteorological Spring

There are two ways to define the start of spring:

Meteorological seasons are preferred for climate statistics because they align better with temperature patterns and simplify data comparison. Astronomical seasons, however, are rooted in precise celestial mechanics and are used in this calculator.

Northern vs. Southern Hemisphere

The same astronomical event is experienced differently by each hemisphere:

How to Use This Calculator

1. Select a year: Choose any year from 2000 to 2038 using the dropdown or the quick-access buttons.
2. Choose hemisphere: Northern Hemisphere uses the March equinox; Southern uses the September equinox as the start of spring.
3. View results: See the exact date, UTC time, live countdown (for future equinoxes), all four seasonal markers, season duration, and a 5-year comparison.

Understanding Your Results

Live Countdown

For upcoming equinoxes, a real-time countdown shows days, hours, minutes, and seconds remaining until the exact moment of the vernal equinox.

All Four Seasons

The seasonal timeline displays the year's four astronomical events (two equinoxes and two solstices), labeled appropriately for your chosen hemisphere. The spring equinox is highlighted for easy identification.

Season Duration

Spring's duration — from the vernal equinox to the summer solstice — varies between hemispheres. Northern spring lasts about 92–93 days, while southern spring lasts approximately 89–90 days, because Earth moves faster in its orbit during January (perihelion) than July (aphelion).

Multi-Year Comparison

The 5-year table shows how the equinox date and time shift across years, making it easy to spot the leap-year pattern and plan ahead.

Spring Traditions Around the World

Frequently Asked Questions

When is the first day of spring?

The first day of spring (vernal equinox) occurs in March for the Northern Hemisphere (typically March 19–21) and in September for the Southern Hemisphere (typically September 21–23). The exact date and time vary each year because Earth's orbital period is approximately 365.2422 days. In 2026, the Northern Hemisphere spring equinox falls on March 20 at 14:46 UTC.

What happens during the vernal equinox?

During the vernal equinox, the Sun crosses the celestial equator moving northward (March equinox) or southward (September equinox). Day and night are approximately equal in length worldwide, each lasting about 12 hours. After the spring equinox, days become longer than nights in the respective hemisphere, and temperatures begin to warm.

Why does the first day of spring change each year?

The first day of spring varies because Earth's orbital period is approximately 365.2422 days, not exactly 365 days. This fractional difference, combined with the leap year cycle, causes the equinox to shift by about 6 hours each year, then jump back when a leap year adds an extra day. Gravitational perturbations from the Moon and other planets also create slight variations.

How long does spring last?

Astronomical spring (from the vernal equinox to the summer solstice) lasts approximately 92–93 days in the Northern Hemisphere. In the Southern Hemisphere, spring (September equinox to December solstice) lasts approximately 89–90 days. The difference occurs because Earth moves faster in its orbit during January than July.

What is the difference between astronomical spring and meteorological spring?

Astronomical spring begins at the vernal equinox (around March 20 in the Northern Hemisphere) and is based on Earth's position relative to the Sun. Meteorological spring always starts on March 1 and is based on the annual temperature cycle, dividing the year into four 3-month seasons. Meteorological seasons are preferred for weather forecasting and climate statistics.

Is the first day of spring the same date worldwide?

The vernal equinox occurs at the same instant worldwide in UTC time. However, due to time zone differences, the local date may differ by one day. For example, if the equinox occurs at 23:00 UTC on March 20, it would already be March 21 in East Asian and Australian time zones. Additionally, the Northern and Southern hemispheres have opposite spring dates.

Additional Resources

• March Equinox — Wikipedia
• Seasons — Wikipedia
• Nowruz — Wikipedia