humid air is less dense than dry air (MW of water is 18 versus 29 for "air") so friction is reduced. it has been especially humid around here for a while and that is just fine with me - sweating is okay, healthy actually. later this summer i'll be down in north carolina, cape fear area, where i have seen the dew point get up to 80 °F. you kind of need to get your riding in before 7:00 am down there.

i love san francisco, but it is not my home.