I had a similar problem about a month ago in Central Wisconsin. A lot of cool damp weather and a weak hive. I was worried and the weather wasn't helping much so I removed the worst frame from the hive and moved some of the other frames around to try to help with the ventilation. I also switched the positions of my two hives to get more bees into the weaker colony. Luckily the weather also changed and a week or two later the bees had taken care of the rest.
Good luck!