Julia Gomez and Mary Walrath-Holdridge, USA TODAY Sat, June 20, 2026 at 7:00 PM UTC 2 min read Add Yahoo as a preferred source to see more of our stories on Google. It's officially the summer solstice which is the longest day of the year and the first day of summer. On Sunday, June 21, at 4:24 a.m. ET, the summer solstice will occur in the Northern Hemisphere, according to NASA. Around this time, the Northern Hemisphere will experience its longest days and shortest nights.