The astronomical definition is likely the one you learned in school. It is based on the Earth’s 23.5-degree axial tilt and its 365-day journey around the sun. Seasons change when the Earth reaches four key points in its orbit: the two and the two equinoxes .
Begins at the Winter Solstice (December 20–23) and ends at the Vernal Equinox. The winter solstice is the shortest day of the year.
Before we dive into the details, here is the quick-reference answer for the Northern Hemisphere:
As the Earth continues its orbit, the tilt moves us away from the sun again.
The dates of the four seasons depend on whether you are looking at the calendar through the lens of or meteorology . 1. The Astronomical Seasons when do the four seasons start and end
The coldest time of the year. Astronomical winter begins when the North Pole is tilted away from the sun. Summary Table: 2026 Season Dates (Northern Hemisphere) Meteorological Start Astronomical Start Spring Summer Fall September 1 September 22 Winter December 1 December 21 3. Meteorological vs. Astronomical: Why the Difference?
Meteorologists (weather scientists) divide the year into four neat seasons made up of three full months each. This makes calculating weather statistics and averages much easier.
definition (based on Earth's position relative to the Sun) or the meteorological
Temperatures begin to drop, and deciduous trees lose their leaves. In many cultures, this is the traditional time for harvesting crops before the frost. 4. Winter (The Season of Dormancy) The astronomical definition is likely the one you
Starts at the Vernal Equinox ( September 21–23 ) and ends at the Summer Solstice ( December 20–23 ). Meteorological: Starts September 1 and ends November 30 .
Definition
In the celestial clockwork of our world, the four seasons aren’t just dates on a calendar; they are the rhythmic breathing of the Earth as it tilts toward and away from the sun. The Awakening: Spring
In the Northern Hemisphere, the dates for the current year are as follows: Meteorological Dates Astronomical Dates (Approx.) March 1 – May 31 March 20 – June 20 Summer June 1 – August 31 June 21 – September 22 Fall September 1 – November 30 September 22 – December 20 Winter December 1 – February 28/29 December 21 – March 19 Two Ways to Define Seasons When Do the Seasons Start and End in 2026? Begins at the Winter Solstice (December 20–23) and
The warmest time of the year. The astronomical summer begins when the North Pole is tilted furthest toward the sun. 🍂 Fall (Autumn) Meteorological Start: September 1, 2026 Astronomical Start: September 22, 2026 (Autumnal Equinox)
The transition between spring, summer, autumn, and winter is one of the most fundamental rhythms of life on Earth. However, if you have ever noticed that the official start of a season changes by a day or two from year to year, or that meteorologists track seasons differently than calendar makers, you are not alone.
Summer begins when the Sun reaches its highest point in the sky, resulting in the longest day of the year.
The start and end dates for the four seasons depend on whether you use the calendar (based on the Earth's orbit) or the meteorological calendar (based on temperature cycles). 2026 Season Dates (Northern Hemisphere)