When Summer Ends 2024. 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. When does summer start 2024 and when is the longest day?

Thursday, june 20 is the official first day of northern astronomical summer for 2024 — summer solstice — which is the longest day of the year for this half of the. Find out the date, how long in days until and count down to till summer 2024 with a countdown clock.