When Does Summer Start 2026. Begins on sunday, september 1, and ends on saturday, november 30. 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.

The schedule of classes for summer 2026, fall 2026, and spring 2027 is available. The summer solstice is the day with the most hours of sunlight during the whole year.