Spring has sprung, Fall hasn't fell

I have been puzzling over a weird phenomenon ever since last fall. Here in my neighborhood in Iowa, there are quite a few trees that still have their autumn leaves hanging on. I’m not talking about a few leaves, some of them have the whole tree worth of leaves, the leaves died but they just didn’t fall off. And they’re still stuck on the trees now. I’ve never seen anything like it.
I have a tree like that in my back yard, and if I pull on a leaf, it pops right off, but I don’t understand why they didn’t pop off in autumn or during the high winter winds. And aren’t these leaves attached at the point where the new buds emerge? That would be like a baby tooth that won’t fall out when the permanent tooth is already erupting.
So does anyone have any wild biological guess on these odd trees?

Maybe they’re mallorns? Seriously, though, they need something to pull on them to come off. Has it just been really quiet, wind-wise? Other than that, I haven’t a clue. Do they do this every year?

I though just gravity was enough to pull em off once it got below freezing and the abcission layer is broken. I don’t think this year’s winter was that different than any other year, but the year before, heavy snow fell before the leaves fell off in autumn, although the leaves did fall that year. No, this is the first time I’ve ever seen anything like this. But today we’re having freakk 45 to 50 mph winds, so I’ll go and check, especially at my neighbors’ trees where he has a whole maple tree that is still full of autumn leaves. The leaves are probably all down now.