It was raining to beat the band.

This expression can be used when it rains so hard that it seems to make enough noise to be louder than a band of musicians.

[雨下得真大。]

本句的意思在誇飾雨下得太大；滂沱雨勢所發出的聲響，大到足以壓過整個樂團的合奏聲呢！