(3) Pluto Explanation: Until it lost its planetary status in 2006, Pluto was the coldest with an estimated surface temperature between -235 and -210 degrees Celsius. But Pluto has now been relegated the status of a Dwarf Planet. Pluto has always had the 'honour' of being the coldest planet with an average temperature between 360 to -400 degrees Fahrenheit. This is because it is so far away from the sun: it is over 40 times further from the sun than planet Earth. Pluto also has no internal heat source and it even orbits in a ring of ice debris.