Originally Posted by Maxvision
Wondering if humidity might be a factor to consider?
There are all sorts of weather factors the play with it though. Since you live in SoCal you probably won't notice the humidity factor like I do in Colorado. I can feel the humidity factor come into play when I ride on the bike paths next to the rivers. There is room for debate whether gravity plays a factor as well. Although the effect would be extremely small, you never know; A way to determine this is compare night riding to day riding.