However, from an astronomical perspective, summer begins on the summer solstice, which typically falls on June 20 or June 21 in the Northern Hemisphere. This marks the longest day of the year and the official start of summer. In this context, June is not fully summer, but rather a transitional month that leads into the peak summer months of July and August.
Meteorologically speaking, summer started June 1st. But socially? Most people don't feel like it's "summer" until they are sweating in a car with broken AC. is june summer
“Is June summer?”