Summer 2025. Summer 2025 starts on friday, june 20th in the northern hemisphere, with the first day of summer being the longest daylight day of the year with the earth's axis having reached its furthest tilt and begins to change. June, july, august and september.
Sign up below to receive application deadline reminders and more information about summer 2025! Harvard summer school offers the opportunity for motivated high school students to take part in a transformative summer, with more than 500 courses to choose from, unique.