When Is The Longest Day Summer Solstice 2024. In the northern hemisphere, the 2024 summer solstice will occur on june 20 at 20:51 gmt (4:51 p.m. In 2024, the summer solstice will occur on june 20, at 20:51 gmt in the northern hemisphere, and on december 21, at 09:20 gmt in the southern hemisphere.

In 2024, the summer solstice will occur at 4:50 p.m. The summer solstice occurs at 21:54.