We have done many Julys. Usually it is HOT as Sonia says but occasionally you get a really potent storm/downpour. They are such FUN! They last almost no time, but suddenly a big contrast from the pure blue sky, hot sun and wherever you are, you just smile, order more food or drink and watch. The rain is warm, and there is no discomfort, just a contrast. And it doesn't happen very often at that time of year. I have heard many more complaints about the heat (I love the heat...) than of rain or downpours in July.
Phil