I'm going on a bike ride today and it will be very humid, up to 78 by noon and eventually up to 89 by 4:00 pm. which is somewhat unusual for us. I plan on wearing mountain bike shorts (Fox "Townie" shorts), but was wondering whether I should wear a short sleeve loose cotton tee shirt or a technical fabric, but tight jersey (Castelli "Perla"). I know that when cotton gets wet you stay soggy, but the top is looser. Tight equates to hot in my mind.

Thanks.