What is the hottest planet in the solar system?

You'd think it's Mercury because it's the closest to the sun but it's not. If you're looking for some hot property in the solar system you should visit Venus.

At a scorching 480° C (896° F) it's the hottest planet. Mercury doesn't have an atmosphere so it can't trap the sun's heat. Venus on the other hand has a dense atmosphere made up of mostly carbon dioxide which is a greenhouse gas. Greenhouse gases trap the sun's heat.

Mercury on a hot day is only 375° C. I'd still recommend you bring plenty of sunscreen lotion.