If the humidity where you are is anything like what I’m experiencing in Kansas City, well . . . you know what it’s like to be outside in air that feels like soup! A common household problem during muggy months is swollen doors, especially if you live in an older home.
I stumbled across a great tip on Young House Love that’s an easy way to use any excess paint you may have on hand. To stop the door from sticking in the door frame (and help it close properly), use a sander to smooth down the top edge of the door.
Once you’ve sanded off enough of the door so that it fits within the frame, apply a thin coat of paint to the top edge and allow to fully dry. The paint acts as a sealant and will help maintain the door’s proper size so that it’s less likely to swell.