Summer Solstice 2025 Longest Day. 20 june will be the longest day of 2025 in the northern hemisphere, midsummer day. Sydney the exact moment of the summer solstice in 2025 is 20 march, at.

It’s the longest day of the year. Summer solstice in the northern hemisphere countdown to 20th june 2025 at 9:44pm (europe/london time)