Longest Day Of The Year 2024 Usa. In 2024, the december solstice falls at 9:21 utc on december 21 (3:21 a.m. On this date, major cities across the nation will see as much as 15 hours of sunlight, with one.

The summer solstice, marking the year’s longest daylight period, officially occurs thursday at 4:51 p.m. The first day of what’s projected to be an unusually hot summer, the longest day of the year and the summer solstice all arrive thursday, june 20.