Last Day Of Summer 2024 Usa Calendar. Find out the date, how long in days until and count down to since summer 2024 with a countdown clock. The first day of summer is also known as the summer solstice, and in 2024 it happens on thursday, june 20 at 4:51 p.m.

It’s the longest day of the year and follows father’s day and juneteenth, which fall. The next change of season.