Keep your powder dry....this is gonna get worse before it gets better.
Don't know about you, but I keep my powder in little brass capsules, with the bullet sealed into the opening. These in turn are in boxes, which are inside of plastic pouches and those are in a wooden crate. Once the plastic pouch is opened, I keep the boxes in green metal cans or black plastic containers which have seals to help prevent moisture from getting inside. My powder is dry.