Summer Solstice 2025 Uk. When is the summer solstice 2025? The northern hemisphere will mark the summer solstice on 21 june, the ‘longest day of the year’, when there will be around 16.5 hours of daylight.
The exact moment of the solstice is at 3.42 am bst, which is the point at which the northern hemisphere is tilted farthest towards the sun. The summer solstice occurs in june in the northern hemisphere and marks midsummer: