Summer Solstice 2025 Day And Date. This is the longest day of the year and marks the start of summer in. Summer begins with the solstice on friday, june 20, 2025, marking the astronomical first day of summer in the northern hemisphere.

On the summer solstice, when the northern tilt is closest to the sun, we have the longest day, usually june 20 or 21. Total solar eclipse over lac brome, quebec, canada on april 8, 2024.