| Season | Northern Hemisphere | Southern Hemisphere | | :--- | :--- | :--- | | | March 1 – May 31 | September 1 – November 30 | | Summer | June 1 – August 31 | December 1 – February 28/29 | | Autumn (Fall) | September 1 – November 30 | March 1 – May 31 | | Winter | December 1 – February 28/29 | June 1 – August 31 |
Every year, the Earth’s journey around the Sun brings us the familiar rhythm of spring, summer, autumn, and winter. But the exact date the seasons change depends on who you ask. There are two main ways to define season change dates: astronomical (based on the Sun’s position) and meteorological (based on temperature cycles). Astronomical Seasons (Solstices & Equinoxes) This is the most traditional method, tied to the Earth’s 23.5-degree tilt. Seasons change on the following four key events: season change dates
| Season | Northern Hemisphere | Southern Hemisphere | Astronomical Marker | | :--- | :--- | :--- | :--- | | | March Equinox (Mar 19–21) | September Equinox (Sep 22–23) | Sun crosses celestial equator northward | | Summer | June Solstice (Jun 20–22) | December Solstice (Dec 21–22) | Longest day of the year | | Autumn (Fall) | September Equinox (Sep 22–23) | March Equinox (Mar 19–21) | Sun crosses celestial equator southward | | Winter | December Solstice (Dec 21–22) | June Solstice (Jun 20–22) | Shortest day of the year | Why the date varies: The astronomical year is roughly 365.2422 days long. The leap year cycle (February 29) shifts the exact date of equinoxes and solstices by a day or two each year. Meteorological Seasons (Based on Climate) Meteorologists and climatologists use a simpler system that aligns with the calendar and annual temperature cycle. This makes record-keeping and forecasting more consistent. | Season | Northern Hemisphere | Southern Hemisphere