Which Planet Is the Hottest? Venus, at About 464°C

Q: Which planet is the hottest?

Venus is the hottest planet in our solar system, with an average surface temperature of about 464°C (867°F), hot enough to melt lead. It’s even hotter than Mercury, which is closer to the Sun, because Venus’s thick carbon dioxide atmosphere traps heat in a runaway greenhouse effect.

Average temperatures of the planets

Planet	Average temperature (approx.)
Mercury	167°C (but ranges from −173°C to 427°C)
Venus	464°C
Earth	15°C
Mars	−65°C
Jupiter	−110°C (cloud tops)
Saturn	−140°C (cloud tops)
Uranus	−195°C
Neptune	−200°C

Why Venus beats Mercury

	Mercury	Venus
Distance from the Sun	Closer	Farther
Atmosphere	Almost none	Very thick, ~96% carbon dioxide
Result	Heat escapes; nights are freezing	Heat is trapped; every place on the planet is about equally hot, day and night

Venus’s atmosphere is so heavy that the pressure at the surface is about 92 times Earth’s, like being 900 meters underwater. Clouds of sulfuric acid cover the planet and reflect sunlight, making Venus the brightest planet in our night sky.

Visiting Venus

The Soviet Union’s Venera landers were the first to land on another planet and send back pictures from the surface, in the 1970s and 1980s. None survived more than about two hours in the heat and pressure.

A warning for Earth?

Scientists think Venus may once have had oceans, before a runaway greenhouse effect boiled them away. It’s an extreme example of how carbon dioxide traps heat, a process happening on a much smaller scale on Earth.

For more planet records, see which planet has the shortest day. Our own Sun is far hotter: how hot is the Sun.