At least two compounds contain repetitions of 雨, the rain radical (known as amekanmuri, 雨冠):
露霜 (tsuyujimo: frozen dew) dew + frost
Frozen dew? Oh, that’s frost! This sample sentence from Breen explains that:
霜は露が凍ったものだ。
Shimo wa tsuyu ga kōtta mono da.
Frost is frozen dew.霜 (shimo: frost)
凍 (kō(ru): to freeze, be frozen over)
零露 (reiro: dripping dew) to spill + dew
The first kanji is a bit of a mystery. You may have heard that rei is one way of saying “zero.” Well, 零 is that “zero.” Halpern lists “zero” as the only meaning of this character, though Breen and Henshall contribute more definitions. Henshall says that 零 once meant “falling rain,” which then broadened to mean “to fall.” The character also meant “raindrops” and evolved to mean “drop” in general. A drop is a tiny and nearly nonexistent thing, so in Japanese (but not in Chinese) 零 came to mean “zero.” We’ll return to this idea next week as it applies to 露.
And then one compound provides 雨 twice in a whale-fish kind of way:
雨露 (uro: rain and dew) rain + dew