Summer ends when August does.
Then again, you're in Finland, aren't you Hitti? I didn't think you had summer there. I thought it was five-six months of perpetual darkness, with temperatures plummeting so low that all your lights freeze over and break, leading to beleaguered Finns groping around in the dark trying to find their way to the local grocers', only to find that there are no vegetables to buy because of the perpetual darkness killing them, so they shuffle back through the six feet of snow, under constant threat from polar bears and Santa, until they return to their darkened log cabins and cry themselves to sleep, except they don't sleep because their tears freeze and stab their eyes, and they run around screaming until they run into a bookcase and get clobbered by a falling dictionary, and since Finnish words are so long their dictionaries are extra-heavy, so they don't survive. Or at least, that's the impression I got.