Next solstice: September equinox, 23 September 2026
The next turning point is the september equinox, on 23 September 2026 at 00:05 UTC — 28 days away. It begins autumn in the northern hemisphere and spring in the southern. Every instant here is computed from the sun's position rather than rounded to a fixed calendar date, so it is right to the minute and right about which day it falls on where you are.
NextSeptember equinox
Every year, every turning point
| Year | March equinox | June solstice | September equinox | December solstice |
|---|---|---|---|---|
| 2024 | 20 Mar 03:06 | 20 Jun 20:51 | 22 Sept 12:43 | 21 Dec 09:20 |
| 2025 | 20 Mar 09:01 | 21 Jun 02:42 | 22 Sept 18:19 | 21 Dec 15:03 |
| 2026 | 20 Mar 14:45 | 21 Jun 08:25 | 23 Sept 00:05 | 21 Dec 20:50 |
| 2027 | 20 Mar 20:24 | 21 Jun 14:10 | 23 Sept 06:01 | 22 Dec 02:42 |
| 2028 | 20 Mar 02:17 | 20 Jun 20:01 | 22 Sept 11:45 | 21 Dec 08:20 |
| 2029 | 20 Mar 08:01 | 21 Jun 01:48 | 22 Sept 17:38 | 21 Dec 14:14 |
| 2030 | 20 Mar 13:51 | 21 Jun 07:31 | 22 Sept 23:27 | 21 Dec 20:09 |
| 2031 | 20 Mar 19:41 | 21 Jun 13:17 | 23 Sept 05:15 | 22 Dec 01:56 |
| 2032 | 20 Mar 01:21 | 20 Jun 19:08 | 22 Sept 11:11 | 21 Dec 07:56 |
Why these are computed and not looked up
A solstice is the instant the sun reaches its furthest point north or south; an equinox is the instant it crosses the celestial equator. Those are positions, so they can be calculated for any year in either direction, and a published table is only somebody else's calculation with the working thrown away.
The method here is the standard one from Meeus's Astronomical Algorithms: a mean instant from a polynomial in the year, corrected by two dozen periodic terms for the pull of the moon and the planets, then shifted from Terrestrial Time to the time a clock reads. Before any of it is published it is compared against an independently written ephemeris built on a different model, across two hundred years and eight hundred instants. They agree to a fraction of a minute. That comparison runs on every build, so a mistake in the arithmetic fails the build rather than reaching a page.
FAQ
When is the next solstice or equinox?
The september equinox, 23 September 2026 at 00:05 UTC. That instant is the same everywhere on earth; the local date can be a day later east of roughly the Atlantic, which is why sources disagree about whether it is the 20th or the 21st.
Why do these dates change from year to year?
The year is about a quarter of a day longer than 365 days, so each seasonal instant arrives roughly six hours later than the last one, and each leap day pulls it back a whole day. Over four years that traces a saw-tooth, which is why the March equinox lands on the 19th, 20th or 21st depending on the year.
Is the solstice the start of the season?
Under the astronomical convention, yes. Meteorologists use whole months instead — spring is March, April and May in the north — because climate records need periods of equal length. Both conventions are in everyday use, which is why two reputable sources can give different answers to the same question.