First Day of Summer 2027

Southern Hemisphere

South of the equator the seasons are reversed, in Australia, New Zealand, South Africa and Argentina alike. In Sydney the June solstice occurs on Tuesday, June 22, 2027 at 12:11 AM AEST. Australia's Bureau of Meteorology uses meteorological seasons, so in Australia winter is usually counted from June 1.

Why the first day of summer changes date

The calendar year has 365 or 366 days, but the tropical year — the time from one June solstice to the next — averages about 365.242 days, roughly 5 hours 49 minutes longer than a common year. So the June solstice 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 46 min
• 2027 → 2028: −18 h 10 min (leap year)
• 2028 → 2029: +5 h 47 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 June solstice

• The Sun reaches its northernmost point and stands directly overhead at local noon on the Tropic of Cancer (about 23.4°N).
• It is the longest day and shortest night of the year in the Northern Hemisphere, and the shortest day in the Southern Hemisphere. Daylight is about 12 hours at the equator and longer the farther north you go; north of the Arctic Circle (about 66.5°N) the Sun does not set at all.
• At mid-northern latitudes the earliest sunrise of the year comes about a week before the solstice and the latest sunset about a week after it.