Summer Solstice 2024 Events Usa. When is the first day of summer in 2024? Usually it's a decent rule of thumb that seasons start on the 21st of the appropriate month, but that's not.

The june solstice marks the first day of astronomical summer in the northern hemisphere and the first day of winter in the southern hemisphere. Astronomical summer officially arrives in the northern hemisphere — amidst a heat wave — at 4:51 p.m.