The summer solstice 2025 for the Northern Hemisphere occurs on June 21. Also known as June Solstice, the day marks the official start of astronomical summer and is the longest day of the year. Many cultures around the world celebrate the summer solstice with numerous traditions, holidays, and festivals. To celebrate June Solstice 2025, share these Happy Summer Solstice 2025 wishes, greetings, quotes, and messages.