The xxxx part may be now 1212 or some other fixed number because of the squeeze on phone numbers. The Phila weather and time services used to be any four digits but now only work on 1212.
The Bell System made a half hearted attempt to standardize weather reports at 936-1212; many cities used that number. In the 1970s they had a bill insert listing the number for a number cities and suggesting calling it before taking a trip (as a way to drum up long distance business). I thought that was a pretty good idea and made use of it.
As mentioned, the AAA Travel Guides listed such numbers in the city writeups. At one time the phone company advertised these services and gave them prominent mention in the telephone directory. However, I suspect they're no longer interested in them, it is a cost after all with little benefit today. I don't see any references in the phone book. Indeed, my local directory lists time of day service available from the operator for something like $1.50 service charge which is far more than calling the city for their time announcement.
I remain curious whether 212-976-1212 is active in New York City. I posted the question on a NYC newsgroup and no one seems to know there either.