Longest Day Of The Year 2025. Countdown to the longest day of the year summer solstice in the northern hemisphere countdown to 20th june 2025 at 9:44pm (europe/london time) At midnight, the evening will culminate in singapore’s longest single countdown fireworks display this year that will illuminate the sky to usher in 2025!

In 2025, it could enter its 124th year of working life. In 2025 the summer solstice will occur on saturday 21 june at 03.42 bst (02.42 gmt).