The weather API isn't exactly dead, it's just locked down. But not securely...

https://www.google.com/ig/api?weather=23220&hl=en&referrer=googlecalendar

The funny thing is that it only works if referrer is "googlecalendar" (so far from what I've tried), but it doesn't care if that's the actual HTTP_REFERER. Just passing it as a request parameter gets the XML response.

I stumbled upon this after getting pissed with the Yahoo API used by https://github.com/Neroth/gnome-shell-extension-weather, which appears to be broken in Fedora repos.