The Seasons Calculator calculates the approximate time and date of the March equinox, the June solstice, the September equinox and the December solstice. These dates mark the beginning of the four seasons of the year in many countries: spring, summer, autumn (or fall) and winter.
It is important to note that the seasons in the northern hemisphere are opposite to those in the southern hemisphere. For example, spring in the northern hemisphere is autumn (or fall) in the southern hemisphere. Therefore the March equinox is known as the spring or vernal equinox in the northern hemisphere and the autumnal equinox in the southern hemisphere. The September equinox is known as the autumnal equinox in the northern hemisphere and the spring or vernal equinox in the southern hemisphere.
Reference to the start of the seasons on this page are taken from an astronomical viewpoint. In meteorological terms the start dates for the seasons are different. So spring in many countries in the northern hemisphere begins on March 1, summer on June 1, autumn (or fall) on September 1, and winter on December 1.
