Summer Solstice 2024 Time Edt. 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. When is the first day of summer 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. For those of us in the northern hemisphere, earth is tilting mostly.