Official First Day Of Summer 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. The first day of summer in the northern hemisphere will be on june 20, 2024.

The 2024 summer solstice arrives june 20 at 4:51 p.m. Residents in the northern hemisphere will experience the longest day of the year on thursday, june 20 due to the sun being at its highest point in the sky that day.