the way the weather's been lately it's prolly just condensation, mine dropped
a couple drops out of each tailpipe and smoked a little from the water heating up

if it was a blown head gasket I doubt the coolant would get all the way to
the tailpipes before you hydrolocked the motor

your car could just be boiling over, I'd do a coolant flush to make sure
nothing is clogging your passages and run the car while you watch all the
coolant lines.