What'S The First Day Of Summer 2024. According to the national centers for environmental information, the two. The summer solstice marks the longest day of the year, with the most hours.
Summer 2024 starts on thursday, june 20th in the northern hemisphere, with the first day of summer being the longest daylight day of the year with the earth’s axis having. 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.