I often bike to work, which for me is about 26 miles each direction. I take a shower right
before I leave, and when I get there I just have to rinse down and change out of my cycling jersey. The theory behind the pre-ride shower is that body odor is caused by bacteria on your skin, and showering temporarily knocks out enough of your bacteria that it won't cause significant odor during your ride. (I'm not aware of actual science on this topic, but I've asked a trusted coworker whether I smell after riding into work, and he says I don't. So there's your anecdotal data point...) So for me the bike is extremely practical even living in an area that
wasn't designed with bicycles in mind.
As for humidity, this is in south Florida—if we can manage it here, then we can handle the humidity pretty much anywhere in the US.
Now I'm not saying everyone can or should bike a 52-mile round trip to work. But the point of this article is that this little experimental suburb has 5,500 people within a single square mile; biking or walking is a perfectly reasonable way to traverse such a small area at nearly any level of fitness, especially when you don't have to worry about automotive traffic, and for the few people who can't manage that there's the public transport option. Even on our hottest days here in south Florida, one can easily bike a mile, fully dressed, without breaking a sweat.