Noise when wet is pretty common. Noise when dry should only be because of pad/rotor mismatch or contaminated pads.

First things I would do is make sure your calipers are bolted on straight(just cuz it's new doesn't mean it was set up right) and rotors are true. Look at the caliper from the rear,and make sure the caliper is straight on the rotor. There are two bolts that go into horizontal slots in the caliper mount;they should be lined up. If not,that's a sure sign the caliper is mounted crooked. Next look down into the caliper from the top or bottom(if the bike is upside-down). Hold the wheel by the spokes and slowly turn it while looking at the rotor between the pads. If the rotor moves to the side and touches a pad,it needs to be trued. To do this,turn the wheel until the rotor touches,then grab the spoke above it,and turn the wheel until that part of the rotor is out in the open(by holding the spoke you'll know where the spot is). Clamp an adjustable wrench to the rotor(DO NOT use pliers or a wrench with teeth,the teeth will score the rotor) and gently bend the rotor in the opposite direction from the side it was touching. Then rotate the rotor back into the caliper and see if it still touches. If it does,repeat bending a touch more. Once it's clear turn the wheel until you've checked the entire circumference of the rotor.