To give any insight at all, people have to know the methodology you are using going about things. The bearding, do you have entrance reducers on? what type of ventilation as well as congestion inside the box/ie how full is it? with a 10 frame, it is purposely made that way to sort of restrict space actually. bees get in there between comb and there isn't much airflow that they do not make themselves, especially going up 3/4 boxes. this has benefits but also has problems. Do you have your boxes out in full sun totally? what color are they, what are they made out of and how thick are they. it all comes into play imo in various amounts. none or it is usually something that cannot be handled though. I'm putting a third deep on 4 of my hives, probably tomorrow. As you say, today is rainy on and off, and I'm not at a emergency situation, so it can wait for me.