When does summer begin ?

Summer officially begins June 21st. Because,  The solstice heralds the beginning of summer in the Northern Hemisphere. In 2015, the summer begins with the solstice on June 21 at 12:38 P.M. EDT. The timing of the solstice depends on when the Sun reaches its farthest point north of the equator.

Hope I helped!

- Amber

On June 21 that's when summer begging and it says in the calendar

Answermaritime tropical;