When they become available again in July get some REI Headwinds pant for those in between times when its below 50 degrees I've worn them in temps down to 32 degrees and they are great, which explains why the are out of stock till July and then change when you get to class. During our week of summer will use convertable pants with the cycling underwear REI they are light and padded enough for my use which is about the same distance as your commute. I find that any pants with a gusseted crotch are fine and just use a dork band to keep the leg out of the chain.