Summer Solstice 2025 Uk. Summer 2025 starts on friday, 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 reached. A solstice is the day when the sun is at its highest or lowest point in the sky.

When is summer solstice 2025. The summer solstice is the longest day of the year, meaning the day of the year that has the most hours of sunlight.