I wear flip-flops from April to November every year, everywhere except work.
Outside of work the standard fare is Hawaiian shirt (or t-shirt if doing chores) and shorts with lots O'pockets and flip-flops.
I attend a casual dress service at church so I can wear sandals there too just like Jesus wore.
EDIT
This may be a regional thing.
In coastal cities or very warm regions flip flops may be more acceptable than in other places.
in So Cal flip flops are as common as bottled water.
Maybe in others places they are not.
it's also very possible that folks who live in places where flip flops are common take better care of their footsies and toe-nails that folks who live ...... elsewhere.
Howz that fer being PC and not telling anyone to go do bad things to themselves?
I'm so pround.