Boy, all of that talk back in March about 'Maybe the heat and sunshine will kill it..." didn't turn out to be true. In fact, looking at the map, it seems the heat and sunshine actually incubate it!
Yes, but you are probably aware of the other interpretation: it spreads so much better indoors. The theory is that if people in the south are driven inside due to A/C, they are more likely to spread it. The bad news is obvious for those of us in the north come winter.