First Day Of Summer 2025 Calendar Dates. Fall begins with the autumnal equinox, sunday, september 22, 2025, 8:44 a.m. United states 2025 holiday calendar with all major holidays and observances.

This year the summer will start on thursday june 20, 2025 (day of the summer solstice) and will end on sunday september 22, 2025 with the autumnal equinox. When do the four seasons start in 2025—for spring, summer, fall, and winter?