When Is Summer Equinox 2025. Edt (2051 gmt), and the summer solstice for the southern hemisphere occurs on dec. At the june solstice, the sun reaches its northernmost point.
Equinox means equal day and night (12 hours each). Summer solstice 2025 (beginning of astronomical summer) on the day of the summer (june) solstice, the solar disk, moving along the ecliptic, will fall into its northernmost.
