When is First day of summer?
In 2027, the first day of summer is Monday, June 21, 2027, at 10:11 AM EDT (U.S. Eastern time).
The longest day of the year in the Northern Hemisphere and the astronomical start of summer. After it, days slowly get shorter.
How the date is set: The June solstice (June 20 or 21).
The date in other years
A short history
The June solstice, also known as the northern solstice, is the solstice on Earth that occurs annually between 20 and 22 June according to the Gregorian calendar. In the Northern Hemisphere, the June solstice is the summer solstice (the day with the longest period of daylight), while in the Southern Hemisphere it is the winter solstice (the day with the shortest period of daylight). During the June solstice, the Sun is directly over the Tropic of Cancer, located in the northern hemisphere.
From Wikipedia’s article June solstice, by its contributors, under CC BY-SA 4.0.
Related days
Sources
- U.S. Naval Observatory: Earth’s seasons Dates
- Wikipedia: June solstice Short history (CC BY-SA 4.0)