Which, to be fair, is based more on geometry than weather. I always got thrown by it also being called “midsummer” in various contexts long ago. 7 weeks around the solstice would mean summer is almost starting.

Sweating your ass off in high heat does not mean it’s summer unless your definition of summer is based on the weather, either way. I’m intrigued by the relatively local definitions for season start/end from elsewhere, but things like monsoon need their due too.