Planet name: Barcelona
Size: Pluto-sized, but mostly water. It is all fresh water. It has one large island, where all of its residents live. Due to this, it is more like one big city than a planet with countries and states. It has never accurately been measured, despite its species' technology.
Average temperature: 77 to 88 degrees Fahrenheit (or 25 to 31 degrees Celsius).
Number of Seasons and season (s): The planet mostly stays at the same temperature all year long, but it still does have two seasons, one in which storms are very common and the other being "normal". During its storm season, flooding is easy but has never happened, mysteriously. If there were major floods, Barcelona could become a sort of "Atlantis Planet".
Main species occupying the planet: Barcelonian Dogs and Barcelonians themselves live on the planet of Barcelona.
Other:
Barcelona has some humorously odd tasting fruit. I wouldn't try the bananas. (Make whatever you want of this.)
Some describe it as a "beachy island planet" and they are not at all wrong.
Tourism in Barcelona is encouraged.
Even though the planet markets its sunsets, they really aren't that spectacular. They are very much like earth sunsets.
The Doctor always wanted to take Rose Tyler to Barcelona. (And perhaps he will.)