Summer Equinox 2024 Date. An equinox is one of two days in the year when the sun crosses the equator and day and night become equal in length. When is the summer solstice in 2024?
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. In 2024 the summer solstice will occur on thursday 20 june at 21.51 bst (20.51 gmt).