Uranus

 Average temperature: -195°C (-320°F) where atmospheric pressure equals sea level on Earth

Average distance from Sun: 2,873 million kilometers (1,785 million miles), or 19 times farther from the Sun than Earth
Diameter: 51,118 kilometers (31,763 miles), Uranus is 4 times wider than Earth
Volume: 68 trillion km3 (16 trillion mi3), Earth could fit inside Uranus 68 times
Gravity: 8.7 m/s², or 89% that of Earth’s
Solar day: 17 Earth hours
Solar year: 30,687 Earth days
Atmosphere: 83% hydrogen, 15% helium, 2% methane and other gases

Uranus' climate

The extreme axial tilt Uranus experiences can give rise to unusual weather. As sunlight reaches some areas for the first time in years, it heats up the atmosphere, triggering gigantic springtime storms, according to NASA.

However, when Voyager 2 first imaged Uranus in 1986 at the height of summer in its south, the spacecraft saw a bland-looking sphere with only about 10 or so visible clouds, leading to it to be dubbed "the most boring planet," wrote astronomer Heidi Hammel in "The Ice Giant Systems of Uranus and Neptune," a chapter in "Solar System Update" (Springer, 2007), a compilation of reviews in solar system science. It was decades later, when advanced telescopes such as Hubble came into play and Uranus' long seasons changed, before scientists witnessed the extreme weather on Uranus.

In 2014, astronomers got their first glimpse at summer storms raging on Uranus. Strangely, these massive storms took place seven years after the planet reached its closest approach to the sun, and it remains a mystery why the giant storms occurred after the sun’s heating on the planet was at a maximum.

Other unusual weather on Uranus includes diamond rain, which is thought to sink thousands of miles below the surface of icy giant planets such as Uranus and Neptune. Carbon and hydrogen are thought to compress under extreme heat and pressure deep in the atmospheres of these planets to form diamonds, which are then thought to sink downward, eventually settling around the cores of those worlds.