When Is Summer 2025 In Usa. Find out the date when summer is in 2025 and count down the days until summer with a countdown timer. This year the summer will start on thursday june 20, 2024 (day of the summer solstice) and will end on sunday september 22, 2024 with the autumnal equinox.

This is the longest day of the year and marks the start of summer in the northern hemisphere. Online calendar of holidays and days off in united states for the summer of 2025.