Summer Solstice 2025 Dates Uk. On the day of the autumn (september) equinox, the sun, moving along the ecliptic, crosses the celestial equator, moving from the northern hemisphere to the southern. At the summer solstice, we have the longest day and the shortest night of the year.

In 2025 the summer solstice will occur on saturday 21 june at 03.42 bst (02.42 gmt). On the day of the autumn (september) equinox, the sun, moving along the ecliptic, crosses the celestial equator, moving from the northern hemisphere to the southern.