There are some local features, principally mists and dews, caused by the anomalous bulk of St Peter's Basilica, the elevation, the fountains and the size of the large paved square.
The Vatican City is the world's smallest state, being only a few acres.
In July 2007, the Vatican agreed to become the first carbon neutral state. They plan to accomplish this by offsetting carbon dioxide emissions with the creation of a Vatican Climate Forest in Hungary.