Calendar Summer. Depending on where you reside, choose summer months: The meteorological seasons consist of splitting the seasons into four periods made up of three.

The four seasons of the year in the united states —spring, summer, fall, and winter — are what determine the weather, the ecosystem, and the hours of daylight throughout the year. Summer 2025 starts on friday, june 20th in the northern hemisphere, with the first day of summer being the longest daylight day of the year with the earth’s axis having reached.