First Day Summer 2024 Date. Usually, when we talk about the first day of summer, we are referring to the astronomical summer which is defined by the earth's axis and orbit around the sun. If you want to get really technical, the exact time of the summer solstice this year is 4:51 p.m.
What are the dates for the four seasons in 2024? 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.