Summer Solstice 2024 In California. Thursday, june 20 is the official first day of northern astronomical summer for 2024 — summer solstice — which is the longest day of the year for this half of the planet. The summer solstice, also known as the june solstice arrives june 20 at 4:51 p.m.
It also lists astronomical sunrise and sunset timings on summer solstice day. The summer solstice for the northern hemisphere occurs on june 20, 2024, at 4:51 p.m.