Here's why:

* Cold: Uranus is the seventh planet from the Sun, making it extremely cold. Its average temperature is a frigid -214 degrees Celsius (-353 degrees Fahrenheit).

* Surrounded by clouds: Uranus has a thick atmosphere made up mostly of hydrogen, helium, and methane. The methane absorbs red light, giving Uranus its blue-green color and creating a thick layer of clouds.

While other planets have clouds, Uranus is the most notable for its extreme cold and thick cloud cover.