The Cantonese slang to vividly, but in a playfully vulgar way, moan about the heavy rain is "lockgousee", literally "(it's) raining dog shit" – without specifying it in singular or plural form. Unlike English, the Chinese word in itself does not have a suffixing signifier to indicate the number of things in reference.
It has been raining heavily here for a day. The rainy weather is not going to change for the better in the coming week. Sigh, lockgousee all day long!