First Day Of Summer 20204 2025. The first day of summer arrives with the solstice this year on thursday, june 20, 2025 at 4:51 p.m. When does summer start in 2025, anyway?
Perhaps the most widely recognized start to the summer season is the summer solstice, which falls this year on thursday, june 20. The winter solstice arrives on december 21, 2025.