Solstice vs. Equinox — What's the Difference?

The zenith or nadir of the sun's annual journey.

The time when day and night are of equal duration.

An event marking the longest or shortest daylight period.

A point in the Earth's orbit where hemispheres receive equal sunlight.

The time when the sun reaches its highest or lowest point.

The onset of spring or fall.

An astronomical event due to the Earth's tilt.

An astronomical event marking the sun's position over the equator.

A point in Earth's orbit around the sun.

A celestial occurrence due to Earth's orbit.

A solstice is an event that occurs when the Sun appears to reach its most northerly or southerly excursion relative to the celestial equator on the celestial sphere. Two solstices occur annually, around June 21 and December 21.

An equinox is the instant of time when the plane of Earth's equator passes through the geometric center of the Sun's disk. This occurs twice each year, around 20 March and 23 September.

Either of the two times in the year, the summer solstice and the winter solstice, when the sun reaches its highest or lowest point in the sky at noon, marked by the longest and shortest days.

The time or date (twice each year) at which the sun crosses the celestial equator, when day and night are of equal length (about 22 September and 20 March).

Either of two times of the year when the sun is at its greatest angular distance from the celestial equator. The summer solstice in the Northern Hemisphere occurs about June 21, when the sun is at the zenith on the Tropic of Cancer; the winter solstice occurs about December 21, when the sun is at zenith on the Tropic of Capricorn. The summer solstice is the longest day of the year; the winter solstice is the shortest.

Either of two points on the celestial sphere at which the ecliptic intersects the celestial equator.

One of the two points in the ecliptic at which the sun is furthest from the celestial equator. This corresponds to one of two days in the year when the day is either longest or shortest.

Either of the two times during a year when the sun crosses the celestial equator and when the length of day and night are approximately equal; the vernal equinox or the autumnal equinox.

A stopping or standing still of the sun.

One of the two occasions in the year when the length of the day and night are equal, which occurs when the apparent path of the Sun (the ecliptic) intersects with the equatorial plane of the Earth; this happens on a day between March 19 and 21 (spring in the Northern Hemisphere, and autumn in the Southern Hemisphere), and on another day between September 21 and 24 (autumn in the Northern Hemisphere, and spring in the Southern Hemisphere); hence, the exact time when the intersection occurs.

The point in the ecliptic at which the sun is farthest from the equator, north or south, namely, the first point of the sign Cancer and the first point of the sign Capricorn, the former being the summer solstice, latter the winter solstice, in northern latitudes; - so called because the sun then apparently stands still in its northward or southward motion.

The circumstance of a twenty-four hour time period having the day and night of equal length.

Either of the two times of the year when the sun is at its greatest distance from the celestial equator

(astronomy) One of the two points in space where the apparent path of the Sun intersects with the equatorial plane of the Earth.

(obsolete)

(rare) A wind]] once thought to occur more frequently around the time of an equinox (sense 1), now known to be a misconception; an equinoctial gale.

(astronomy) A plane]] of the Earth's equator (the equatorial plane); also, the Earth's equator.

The time when the sun enters one of the equinoctial points, that is, about March 21 and September 22. See Autumnal equinox, Vernal equinox, under Autumnal and Vernal.

Equinoctial wind or storm.

Either of two times of the year when the sun crosses the plane of the earth's equator and day and night are of equal length

(astronomy) either of the two celestial points at which the celestial equator intersects the ecliptic

An equinox is when day and night are approximately equal in length worldwide because the sun is directly over the equator.

Equinoxes occur twice a year, marking the start of spring and autumn.

A solstice marks the time when one hemisphere experiences its longest or shortest day due to the Earth's tilt.

The summer solstice occurs when one hemisphere is tilted most directly towards the sun, resulting in the longest day.

While solstices mark extreme sun positions, temperature changes might lag due to factors like oceanic heat retention.

Many cultures have festivals or rituals marking solstices, like midsummer or Yule celebrations.

once in summer and once in winter.

During an equinox, all locations on Earth experience roughly 12 hours of daylight and 12 hours of darkness.

They are pivotal points marking the change of seasons and are often used to align traditional calendars.

Yes, during the equinox, the sun is directly above the equator, leading to roughly equal day and night lengths.

Equinoxes are crucial for recalibrating observational tools and understanding Earth's orbit dynamics.

Yes, traditions like the Easter celebrations or Nowruz often align with the equinoxes.

While they roughly occur around similar dates, slight variations can happen due to the Earth's axial precession.

Yes, the extremes of the sun's path during solstices provide insight into Earth's tilt.

Many natural phenomena, like bird migrations or plant blooming cycles, are influenced by the changing light and temperature conditions brought about by solstices and equinoxes.