And right you are. My bad.
Well, y'know, the context is Shakespeare, and in his day, and before, and ever since, the timing of midsummer on the calendar hasn't made sense, OTOH, we don't know their climate as we do our own. The British Isles are pretty high latitude, but are warmed by (I guess it's still called) the Gulf Stream, sufficient to make it possible to grow palm trees in parts of western Scotland.
They also drink their beer warm, and spell aluminum "aluminium".