The hottest planet in the solar system is Venus, with an estimated surface temperature of 864 F (462 C).
The second planet from the sun and Earth's closest neighbor, Venus is famously known for being the brightest object in our night sky aside from the moon. Venus is very similar to Earth both in size and in gravity levels. It is a terrestrial planet and is visible to the naked human eye.
One of the most fascinating facts about Venus is the planet's day and year length. One rotation on Venus lasts for the equivalent of 243 Earth days, which is the longest length of any planet in the Solar System! Interestingly, Venus takes 224.65 Earth days to complete a revolution around the Sun. This means that a day on Venus is technically longer than a year.
The composition of Venus is similar to that of planet Earth. It has a rocky surface and an iron core at its center. The atmosphere of Venus is mostly made out of carbon dioxide. The planet has a very strong greenhouse effect, which results in a very high average temperature. The average temperature of Venus is 864 degrees Fahrenheit (or 462 degrees Celsius). Venus is the hottest planet in the Solar System, even though Mercury is technically closer to the sun.