Summer Solstice 2024 Longest Day Of The Year. In the northern hemisphere it takes place between june 20 and 22, depending on the year. In 2024 the summer solstice will occur on thursday 20 june at 21.51 bst (20.51 gmt).

When is the summer solstice in 2024? The summer solstice marks the start of astronomical summer and the longest day of the year.