amount of rainfall; rainfall amount
Technical and everyday term for the measured quantity of rain that falls over a given period.
今月の降雨量は平年より多い。
This month's rainfall amount is higher than average.
気象庁が年間降雨量のデータを発表した。
The Meteorological Agency released data on annual rainfall amounts.
降雨量 also means rainfall amount and is narrower in scope than 降水量, which includes snow and other precipitation types.
Compound of 降雨 (こうう, 'rainfall') and 量 (りょう, 'amount').