Re: Current weather
It's a little more than a theory, though I don't know if it applies to bananas. On fruit and nut trees, they can suffer significant damage if the encounter freezing weather when they are not dormant. The phloem will freeze and cells rupture. Damage to my leaves are very apparent but just don't show up very well in those photos. I'll try to take more.
The frosty weather results in leaves dropping off of my chestnuts and pomegranates which means I'll soon get busy pruning. One year we had fierce winds and rains that blew over some chestnut trees as they hadn't dropped off their leaves yet. That certainly won't be a problem this year.