Melbourne today has been sweltering under app. 40c temperatures with nearly that yesterday as well. In other words, it’s been stinkin’ hot! 
However, due to our climatic variables, a ‘cool change’ swept in about an hour ago, reducing temperatures by about 15c in as many minutes. The ‘changes’ come in mostly from the south west (from the Southern Ocean), and often bring rain and thunderstorms, but not always. Today it is just cooler air, and it is a blessed relief. Our hot spells (of this magnitude) rarely last longer than three or four days before the change hits.
I was wondering about how these things work where you live. Do you have days of heat followed by such a rapid cool change? Do you have to endure longer spells of bastardly weather? When a change does come, where does it come from? BTW, I guess it’s not just hot weather I am asking about: for those of you with bitter cold and snowstorms and such, when it ‘warms up’ (apart from seasonally) what causes such a change for you?
