Laurence Edwards explains why condensation forms in beehives and when it matters. Side and corner condensation is harmless, but drips onto the bee cluster in the center can cause health problems. Bees use moisture to break down stored honey over winter.
Condensation like this will naturally form in a beehive, whether it's wood or poly. This one here is trapped behind the runner, but it's no problem. The bees will just come up here, use it to break down the stores over winter. Don't get too worried about condensation if it's over in the corner. You don't want condensation forming in the center of the colony there, else it will drop onto the cluster, and that's when it causes issues. Over by the side, really wouldn't worry about it too much.
