I live in Utah where it's around 100F all summer, and we keep the house at 80F or so. Counter storage is totally fine, just keep it covered (we use a glass butter tray), out of the sun, and use it within a couple weeks.

No issues here and we've been doing this for a decade or so.

yes, sort of. new england. so 100f a few day of the year, maybe a couple weeks, but mostly cool.