Whens The Last Day Of Summer 2025. In 2025 the summer solstice will occur on saturday 21 june at 03.42 bst (02.42 gmt). Find out the date, how long in days until and count down to till summer 2025 with a countdown clock.

On that day, the autumnal equinox will occur, marking the beginning of fall. The winter solstice is the day of the year that has the least daylight hours of.