Ciudad Valles is in the mountains and can get chilly. This is where the Micos, Salto, Santa Maria rivers are. We have fires every night, it gets that chilly. The water temps are not to bad, but I still wore a drytop with light layers. It warms up as you get closer to Vera Cruz, but the bugs get bad. And jungle bushwacking can take a toll on your legs, hence da pants.