cosmopolitan

'containing or having experience of people and things from many different parts of the world' https://dictionary.cambridge.org/dictionary/english/cosmopolitan

An English woman walks into an Indian Bazaar in an Italian city to purchase Pakistani produce and what do the woman and shopkeeper talk about...the weather of course.

At present it seems to be hot across all of Europe. Yet in India it is raining, according to the shopkeeper. Water entered his house apparently, not good.

So wherever you find yourself, it seems the most reliable conversation starter, no matter what, is the weather.