Summer starts at the Summer Solstice which is the longest day of the year.
- On or near June 21 in the Northern Hemisphere in the regions of U.S., Central America, Canada, Europe, Asia and Northern Africa.
- On or near December 21 in the Southern Hemisphere in the regions of Australia, New Zealand, South America and southern Africa.
The Summer Season comes after Spring and is followed by Fall & Winter. The 4 seasons are based on how the earth orbits the sun with the solstices being the time with the longest daylight or shortest daylight.