Calendar summer begins on the solstice, but actual meteorological or agricultural summer (the older of the two definitions) has its midpoint on the solstice. Summer builds up the longest day of the year, reaches its apex with that longest day, and then begins to descend and diminish into autumn.
I wonder why the hottest days are then post-solstice? Here we don't really get full summery weather until mid or late June, and it's all done usually by late August. It's really about 2 months of what I consider full summer with the peak in mid-July.
Anyways I had a blast, if I remember correctly. Sitting by the bonfire through the nightless night, plenty of drinks and beautifull ladies in floral pattern dresses and traditional midsummer dances...