The dates above apply to the Northern Hemisphere (North America, Europe, most of Asia). If you are in the Southern Hemisphere (Australia, South America, parts of Africa), the seasons are reversed:
This method is based on the Earth's tilt and its orbit around the Sun. The dates change slightly every year because the Earth's orbit is not exactly 365 days. The seasons are defined by Solstices (longest/shortest days) and Equinoxes (equal day and night).
You may hear people say that seasons actually begin "mid-month" (e.g., February 1st marks the start of Spring in some Celtic traditions). when do the four seasons start and end
Meteorologists and climatologists use fixed calendar dates for simpler record-keeping and forecasting. These seasons align more closely with the annual temperature cycle. The dates are fixed and do not vary by year.
| Season | Astronomical Start (approx.) | Astronomical End (approx.) | Meteorological Start | Meteorological End | | :--- | :--- | :--- | :--- | :--- | | Spring | March 20 | June 20 | March 1 | May 31 | | Summer | June 20 | September 22 | June 1 | August 31 | | Autumn | September 22 | December 21 | September 1 | November 30 | | Winter | December 21 | March 20 | December 1 | February 28/29 | The dates above apply to the Northern Hemisphere
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.
Best for: Gardening, tracking weather patterns, and simplicity. Autumn begins when the Sun crosses the celestial
Autumn begins when the Sun crosses the celestial equator moving south.
To complicate matters further, different cultures around the world define seasons in their own unique ways.