What Is The Coldest Planet Ever?

In terms of planetoids the coldest object in our solar system would be Pluto, with temperatures as low as -210 to -235 degrees Celsius on the surface. However, since Pluto has been relegated from the status of being a planet the coldest planet in our solar system would be Neptune with mean surface temperatures of around 55 Kelvin. There may be other extrasolar planets in the universe whose temperatures may be lower than Neptune but currently we are limited by our technology and have only been able to make educated guesses and speculations about the extrasolar planets that have been discovered so far.