That's rather a difficult question. Since we have explored so few planets, we have no way of making a totally accurate statement. It is presumable that the further away from the sun a planet is, the colder. By this logic, it can be said that Sedna is the coldest body in the solar system. However, since we have not explored the Oort Cloud, we cannot make a more informed estimation or measurement.
The planet with the lowest average temperature in our solar system is Neptune. Its temperature can drop as low as -360°F (-218°C).
Neptune(If you include dwarf planets it is Eris)
Technically speaking, Neptune is the planet with the lowest surface temperature; however, Neptune does not have a solid surface.
Saturn.
Venus.
The planet with the lowest average temperature in our solar system is Neptune. Its temperature can drop as low as -360°F (-218°C).
Neptune(If you include dwarf planets it is Eris)
Technically speaking, Neptune is the planet with the lowest surface temperature; however, Neptune does not have a solid surface.
pluto
Saturn.
Mercury has the second lowest density of any planet in the solar system. Saturn has the lowest density of any other planet.
What is the average tempurature for every planet in the solar system?
Venus.
Neptune is farthest from the SunUranus is the coldest planet in our solar system
Venus
Temperature.
Temperature.