Sarah J.

In North America, these cocktails are still 'autumnal'. It's not like courgette vs. zucchini where you'd probably get a blank stare if you say 'courgette' to most people (in the US at least), both 'fall' and 'autumn' are used to describe the season in North America. 'Fall' has the benefit of being shorter, which likely leads to it being more common.