Almanac · Seasons
Equinoxes and solstices
Next when this page was built: the December solstice 2026, on Mon 21 Dec 2026 at 20:50 UTC.
2026
| Event | When (UTC) | Begins | Day at 60°N | Day at 45°S |
|---|---|---|---|---|
| March equinox | spring in the north, autumn in the south | 12 h 13 min | 12 h 10 min | |
| June solstice | summer in the north, winter in the south | 18 h 52 min | 8 h 46 min | |
| September equinox | autumn in the north, spring in the south | 12 h 11 min | 12 h 11 min | |
| December solstice | winter in the north, summer in the south | 5 h 52 min | 15 h 37 min |
2027
| Event | When (UTC) | Begins | Day at 60°N | Day at 45°S |
|---|---|---|---|---|
| March equinox | spring in the north, autumn in the south | 12 h 11 min | 12 h 10 min | |
| June solstice | summer in the north, winter in the south | 18 h 52 min | 8 h 46 min | |
| September equinox | autumn in the north, spring in the south | 12 h 12 min | 12 h 10 min | |
| December solstice | winter in the north, summer in the south | 5 h 52 min | 15 h 37 min |
2025, past events
| Event | When (UTC) | Begins | Day at 60°N | Day at 45°S |
|---|---|---|---|---|
| March equinox | spring in the north, autumn in the south | 12 h 14 min | 12 h 09 min | |
| June solstice | summer in the north, winter in the south | 18 h 52 min | 8 h 46 min | |
| September equinox | autumn in the north, spring in the south | 12 h 15 min | 12 h 08 min | |
| December solstice | winter in the north, summer in the south | 5 h 52 min | 15 h 37 min |
The Earth’s axis is tilted to its orbit, so through the year the Sun climbs to the north of the sky’s equator and back south of it. A solstice is the instant it stands farthest north or south, and the day is longest in one hemisphere and shortest in the other; an equinox is the instant it crosses the equator, and the day is close to twelve hours everywhere. Each is one instant for the whole Earth, which falls on a different date in different time zones. Why we have seasons walks through it on the sky.
How it is worked out: each instant is the moment the Sun’s apparent longitude reaches 0°, 90°, 180° or 270°, from the Earth’s place in VSOP87, the theory the map sees the planets from, with precession, nutation and aberration, as Meeus works these instants out. The tests hold every one to the U.S. Naval Observatory’s times within the minute. Day lengths are sunrise to sunset, as /tonight gives them. The method.