What and When Is the 2026 Spring Equinox? Equinox Marks Start of Astronomical Spring
The 2026 spring equinox marks the start of astronomical spring in the Northern Hemisphere and falls on March 20 this year; listings show differing exact times for the event. The equinox is the moment the Earth’s tilt is neither toward nor away from the Sun, producing nearly equal sunlight for both hemispheres.
Equinox: How It Happens
The Earth’s axis is tilted by 23. 5 degrees, and that tilt relative to the Sun changes as the planet orbits. At the equinox the tilt reaches a point in which it is neither tipped toward nor away from the Sun, so roughly equal sunlight reaches the Northern and Southern hemispheres. The word equinox comes from Latin: equi means “equal” and nox means “night. “
Equinoxes occur twice a year, in March and September, and they happen at the same moment everywhere on the planet. On the equator the Sun is directly overhead at noon. These are the only times when both poles receive sunlight simultaneously. Around the world, equinoxes have long been marked and celebrated; some cultures observe public holidays and seasonal rituals tied to the event.
When the 2026 spring equinox Occurs
In the Northern Hemisphere the spring equinox falls between March 19 and March 21 in any given year. For 2026 the date is March 20. Timings in available listings differ: one gives 14: 45 for the moment of the equinox, while another lists Friday, March 20 at 10: 46 am ET. The equinox is the instant the Sun is directly above the equator, so that single moment applies worldwide even if clock times vary by location and time zone.
When the equinox occurs in the Northern Hemisphere it marks the start of astronomical spring; in the Southern Hemisphere the same event marks the start of autumn. From the equinox onward, days in the Northern Hemisphere will grow longer each day until the June solstice.
Daylength, the Equilux and Seasonal Labels
It is common to assume the equinox produces exactly 12 hours of daylight and 12 hours of night, but the reality is more nuanced. The official equinox measurement uses the moment the center of the Sun is on the horizon, which yields 12 hours between sunrise and sunset. However, the top edge of the Sun becomes visible before the center rises and disappears after the center sets, and atmospheric refraction extends daylight slightly. As a result, the date when day and night are truly equal in length often occurs a few days before the equinox; this date is known as the equilux. In one documented example for the UK, the equilux falls on Wednesday 18 March.
Separately, weather forecasters use a different seasonal convention: meteorological spring begins on March 1, with March, April and May designated as the spring months to allow consistent year-on-year weather comparisons. Astronomical spring, by contrast, begins at the equinox and will shift slightly from year to year because of the details of Earth’s orbit.
Looking ahead, the equinox is a fixed astronomical milestone that clarifies seasonal timing even when local weather may lag behind. Observers at different latitudes will notice different immediate effects, but the equinox remains the global marker for the astronomical start of spring in the Northern Hemisphere and of autumn in the Southern Hemisphere.
