I have a set of Pronto wipers on my Camry, got them 7 months ago and they've been in Arizona heat, they still wipe fantastically.
How would you know? I spent about two weeks on Thunderbird and 19th in 2012. I think it was July the Fourth it rained. You had to be perfectly still to hear it and I dont think it even hit the ground. Im almost certain it didnt even register officially. It was neat. But, when there I saw some residential houses with rocks for a lawn instead of grasses.
I kept hearing about the monsoon season, whatever that is, but maybe you were referring to using your washer fluid..
It does rain every once in a while, but I use a lot of washer fluid and keep my windshield clean. They're like brand new.