白雨 is read as はくう (hakuu) and means rain shower.
はくう
hakuu
こくふうはくう
sudden rain shower in a dust storm
はくじん
unlicensed prostitute
はくしょ
white paper (government report)
しろ
blank space
しろい
white
しろばい
motorcycle police
しらこ
albino
しらむ
to grow light
はくじつ
bright sunshine
しろみず
color of water after washing rice (colour)
しらき
plain wood
こあめ
light rain