Meanwhile, in Sao Paulo we are getting to 34C (93F) every day, and even the nights have been extremely warm. And here at the southern hemisphere it's winter now.
At São Paulo, it should be usual to have days where the maximum temperature is around 15°C, but most should reach high 20's. It should rain a lot of the time too, but with a small amount of water.
But hot and dry days are not unheard of, they are just unusual.
I'm sorry you guys are experiencing this. I hope that my question isn't foolish, but is it possible that the deforestation in the Amazon is partially causing the reduced rain?
First, the forest covering of the Amazon didn't change that much on the last few years. Don't let international press fool you, the forest isn't "all burning down". It's burning down a lot, but not that much.
But more importantly, the rain on that region is mostly from oceanic and local humidity (São Paulo is in a forest area, with plenty of rivers).
It rains less there in La Niña years. I don't know how abnormal the situation really is. But the heat is way more unusual than low humidity.
The expansion is as a fraction of length. For steel its around 10-20ppm per degree C.
So a 40 degree temperature swing would be 400-800ppm, which means about 1mm difference in length for 2m of steel. Obviously bridges aren't usually made of a single span of steel, but there will be limits to how much expansion a given joint can tolerate, and each half of a draw-bridge needs to be fairly rigid. On top of that, 40 degrees is probably much less than the difference in road temperature between a cold night in January vs. a sunny day in August.
Railway tracks used to buckle in the heat before they built them with a small gap between the rail spans.