How Hot Is Uranus?

How cold is Uranus?

Brutally cold. According to NASA, Uranus's upper atmosphere can drop to about -371°F (-224°C), the coldest measured planetary atmosphere in our solar system. The average temperature near the cloud tops is around -320°F (-195°C). The interior gets warmer with depth, but only modestly compared to Jupiter or Saturn. Uranus's overall internal temperature is much cooler than expected for a planet of its size, which is one of the unsolved mysteries of the outer solar system.

Is Uranus really colder than Neptune?

Yes, slightly. Neptune sits much farther from the Sun than Uranus (Neptune at 30 AU vs Uranus at 19 AU), so you'd expect Neptune to be the colder of the two. Instead, Uranus has lower minimum temperatures and a colder average upper atmosphere. The difference is real but small, just a few degrees at the cloud tops. The puzzle isn't that Uranus is cold; it's that Uranus is cold despite being closer to the Sun, suggesting something unusual is happening to its internal heat.

Why doesn't Uranus emit much heat?

Nobody knows for sure. The other gas and ice giants (Jupiter, Saturn, Neptune) all radiate more heat than they receive from the Sun, mostly from leftover energy from their formation. Uranus barely radiates any extra heat at all, emitting only about as much as it receives from sunlight. One leading theory is that the ancient impact that tilted Uranus sideways also disrupted the planet's interior heat flow, possibly creating stratified layers that trap heat in the deep interior. Another theory suggests Uranus's interior is unusually structured to suppress convection.

Does Uranus have weather?

Yes, despite the cold. Uranus has wind, storms, and seasonal weather changes, though most of it is hard to see through the planet's thick atmospheric haze. Wind speeds can reach about 560 mph, though they're slower than Neptune's. The James Webb Space Telescope has captured detailed images showing seasonal storm activity, polar caps, and dynamic atmosphere features. Uranus's extreme axial tilt (97.77 degrees) gives it very strange seasonal patterns, with each pole experiencing 42 years of sunlight followed by 42 years of darkness.