Equinox 2025
Spring equinox March 20 and fall equinox September 22, 2025. See exact times, what causes equinoxes, and how daylight changes.
🌸 Equinox: 2 events listed below with dates, times, and details. See the countdown and full schedule below.
Vernal equinox — day and night are nearly equal. Spring begins in the Northern Hemisphere.
Autumnal equinox — day and night are nearly equal. Fall begins in the Northern Hemisphere.
About this equinox event
An equinox occurs when Earth's axis is tilted neither toward nor away from the Sun, putting the Sun directly above the equator. The result: nearly 12 hours of daylight and 12 hours of night everywhere on Earth. The 2025 equinoxes fall on March 20, 2025 and September 22, 2025.
Benefits
- ·Shows exact equinox times in Eastern Time
- ·Identifies which hemisphere starts spring vs. fall
- ·Explains the slight day-length asymmetry (true 12-hour balance is the equilux)
- ·Pairs with sunrise/sunset times for any city
- ·Counts down to the next equinox in real time
How it works
The Sun crosses the celestial equator twice a year — moving north in March (vernal equinox) and south in September (autumnal equinox). Because Earth's atmosphere refracts light and the Sun has angular size, the actual day-night equality (the "equilux") happens a few days off the astronomical equinox.
NASA and the US Naval Observatory publish authoritative equinox times. The dates drift slightly from year to year because Earth's tropical year is 365.2422 days. Leap years correct most of the drift; the rest causes the equinox to fall on March 19, 20, or 21 depending on the year.
Who uses this equinox event
Solar gardeners aligning plantings, equinox photographers, astronomy teachers, and anyone tracking seasonal markers across the year.
Equinox 2025
Spring equinox March 20 and fall equinox September 22, 2025. See exact times, what causes equinoxes, and how daylight changes.
Related
Frequently asked questions
What time exactly do the 2025 equinoxes occur?
Exact equinox times for 2025 are listed above in Eastern Time. The equinox is a single moment, not a day — it's when the Sun crosses the celestial equator. NASA and the US Naval Observatory publish times to the second. Times are the same worldwide; the date may vary by timezone.
Why do day and night seem unequal even on the equinox?
Atmospheric refraction bends sunlight, so the Sun appears above the horizon when geometrically below it. The Sun's angular size also gives ~3 minutes of extra "day" at sunrise and sunset. The actual equal day-night moment ("equilux") is several days off the astronomical equinox depending on your latitude. Mid-latitude equilux is typically March 17 and September 26.
Why do the 2025 equinoxes fall on March and September specifically?
Earth's axis tilts 23.4° from the orbital plane. Twice per year — at the March and September equinoxes — the axis points neither toward nor away from the Sun, so the Sun appears directly above the equator. 2025 dates are in March and September because the orbital geometry is fixed; only the exact time-of-day shifts year to year.
Do equinoxes have cultural meaning beyond astronomy?
Yes — Persian Nowruz (New Year) is celebrated on the spring equinox. The Mid-Autumn Festival in Chinese tradition aligns with the September equinox. Neopagan Wicca celebrates Ostara (March) and Mabon (September). Ancient cultures (Egyptian, Mayan, Roman) all built monuments aligned to equinox sunrise. Modern Mexico draws crowds to Chichén Itzá each March equinox to watch the "feathered serpent" shadow descend.