The American climate is also different from the Dutch one. The Wisconsin city that I live in has temperatures that are both 15 F hotter and colder than typical northern European cities. And we commute roughly twice as far because our cities are more spread out.

I'm fortunate that I don't sweat very much, my commute is only 4 miles each way, and I can tailor my schedule around the weather. So I start out early before the sun has cleared the trees, and ride slowly. As a result I'm not particularly sweaty when I arrive at work. Also, I have a casual-dress job with no public interaction.

I live on a street that happens to be a preferred route for cyclists commuting to and from the downtown area. So I see a lot of people on bikes. Most of the commuters are in fact just wearing normal street clothes. I don't even own any cycling-specific clothing.