First Day of Spring 2027

Southern Hemisphere

South of the equator the seasons are reversed, in Australia, New Zealand, South Africa and Argentina alike. In Sydney the March equinox occurs on Sunday, March 21, 2027 at 7:25 AM AEDT. Australia's Bureau of Meteorology uses meteorological seasons, so in Australia autumn is usually counted from March 1.

Why the first day of spring changes date

The calendar year has 365 or 366 days, but the tropical year — the time from one March equinox to the next — averages about 365.242 days, roughly 5 hours 49 minutes longer than a common year. So the March equinox comes about six hours later on the clock each year, and every leap day pulls it back by about 18 hours. Leap years therefore keep it within a two- or three-day window instead of drifting through the calendar. The Gregorian rule that skips leap days in century years not divisible by 400 (1900, 2100) keeps the window from creeping earlier over the centuries.

Change in clock time from one year to the next:

• 2026 → 2027: +5 h 40 min
• 2027 → 2028: −18 h 08 min (leap year)
• 2028 → 2029: +5 h 45 min

The year-to-year change is not exactly 5 h 49 min because the Moon and planets slightly perturb Earth's orbit.

The Sun and daylight on the March equinox

• The Sun crosses the celestial equator heading north and stands directly overhead at the equator at local noon. It rises close to due east and sets close to due west everywhere on Earth.
• Day and night are each close to 12 hours almost everywhere. Daylight is in fact a few minutes longer, because sunrise and sunset are timed from the Sun's upper edge and the atmosphere bends sunlight over the horizon. At mid-northern latitudes the day with equal daylight and darkness (the “equilux”) comes a few days before the March equinox.
• From the March equinox to the September equinox, days are longer than nights in the Northern Hemisphere, and they keep lengthening until the June solstice.
• At the North Pole the Sun rises around the March equinox and stays above the horizon for about six months; at the South Pole it sets.

In 2027, US clocks spring forward for daylight saving time on Sunday, March 14, 2027, 6 days before the equinox.