First Day Of Summer 2024 Usa Time. The summer solstice is nearly here, and we're sharing all of the details about the first day of summer—take a look! It's the longest day and shortest night of the calendar year in the northern hemisphere because it has the longest period of sunlight hours.
Winter begins with the winter solstice, saturday, december 21, 2024, 4:21 a.m. The first day of summer this year is thursday, june 20.