But if you ask most Americans or check school vacation calendars, they’ll simply say: .

In the United States, summer is traditionally considered to include the months of . This matches the meteorological summer, which is based on the annual temperature cycle.

However, there’s a small twist: astronomical summer starts on the summer solstice (around June 20 or 21) and ends on the autumnal equinox (around September 22 or 23). So by that definition, summer includes most of June, all of July and August, and a part of September.