SciShow Space on Youtube shows that on planet earth it rains water, on the exoplanet WASP-76b, it rains liquid iron. But, no matter what planet you're on, the rain drops there have a lot more in common than you might think.
The rain on other planets has very different chemical compositions. On Venus, it rains sulfuric acid. On Mars it snows dry ice, which is carbon dioxide in a solid state. Saturn's moon Titan rains methane, and on Jupiter, it rains helium and mushy ammonia hailstones.
It seems that there is indeed rain falling from clouds on other planets, but it's not water. According to the findings, diamond rain falls on Saturn, Neptune and Jupiter, among others, but Saturn might have the best conditions for it.
It seems that planet Earth is the "only planet" that has liquid water. There is indeed rain falling from clouds on other planets, but it's not water.
About 1,000 tons (907 metric tons) of diamonds a year fall on Saturn. It's still an unpublished theory. This is a theory by planetary scientists at the NASA Jet Propulsion Laboratory. It seems to be unproven.
Over on Titan, Saturn's largest moon, there are icy methane rainstorms. Just as Earth has a water cycle, Titan has a methane cycle. There are seasonal rains. The methane rain fills up lakes. The lakes eventually evaporate and the vapor ascends into the clouds, starting the whole thing over again. Methane is in its liquid form on Titan because the surface temperature is an extremely cold chilly minus 290 degrees F (minus 179 C). There are also cold solid-ice mountains on Titan.