I can replicate your weather one! I think it's taking "this week" extremely literally and the week ends on Saturday. Asking for "this weekend" gives Saturday and Sunday. Asking for the next few days gives 3 days out, etc .
Definitely not addressing the spirit of the request.
GP said they were in Sydney. As far as I know, the week officially starts on Monday in Australia. That's also the case for most of Europe, BTW. Maybe their locale wasn't set right or it's another case of American software assuming weird American standards for the rest of the world.
Yes, the weekend is Saturday and Sunday in the United States. I guess you could consider it like "bookends", for us it's the start and end of the week.
<rant>Google is seemingly giving up on localization entirely. The whole world gets to be Yankee.
It's now started giving me F temperatures on my homescreen, for no particular reason. It knows I'm in Canada. I have set my units in the past to metric. What gives?
I still don't have Canadian English as a locale in Android or Chrome, after what, 15 years of Android? It's got words highlighted all over my page here as mis-spellings. They're not. I really did mean to type colour you piece of crap. I can switch to British but then get spanked for colourize instead of colourised etc.
And it seems to tie choice of English variant to things like pronounciation of words and accent for voice assistant. My car speaks to me in a British accent because I have it set to British English (the closest thing to my own spellings).
They never even tried to handle the facts of the (40M person) Canadian bilingual market. Navigation is either French or English, but many Canadian road sides are in both and it tries to read them out and butchers the pronounciations. Drive into Quebec and have your phone set to English and it's laughable what it does. (Notably doesn't do this for Spanish words in the US, which it seems to have no problem with).</>
Definitely not addressing the spirit of the request.