In Russian, one can ask "там холодно?", literally is it cold there? and "там" is assumed to refer to outside (unless a suitable referent is in the context). The construction can be used in other weather-related questions and statements, e.g. "там снег" it is snowing outside (lit. there). This question is specifically about там meaning "outside" rather than "there" in situations when it has no referent in context.
I checked with a native and could not get her to accept non-weather-related sentences with this construction, e.g. "там много людей" there are many people outside (it can be used when там has a referent). She also rejected "там будет снег сегодня?" will it snow today? (also can be used with a referent), so the construction is really rather restrictive.
I would be tempted to analyse this as a case of degrammaticalization: там is a deictic adverb, but gets used non-deicticly, "outside". It is perhaps also worth noting that other translations for "outside" are complicated in some sense: на улице on the street has four syllables (not sure if this would be a reason for там to take over functions) and снаружи outside can only be used when you are in a closed space (i.e. not when the windows are open).
I am aware that degrammaticalization is rare. And I must admit to poor knowledge of Russian. I do not know the origins of там. Is there something to say for an analysis of degrammaticalization in this case?