Vatican City has no administrative divisions.It could be considered an administrative division of Rome, but because it is its own country it is (mostly) administratively independent of Rome.
The Vatican climate is the same as Rome's; a temperate, Mediterranean climate with mild, rainy winters from September to mid-May and hot, dry summers from May to August.
The Vatican City actually has its own coins - the Vatican Euro. This has been the currency since January 1, 1999. Prior to this the currency was the Vatican Lira. This was equivalent to the Italian Lira at the time. The Vatican City had an agreement with the Italian government, whereby Italian Lira were welcomed in the Vatican City and vice versa.