Nouns ending in -ie are usually feminine.
The suffix often names an abstract quality, an activity, or a discipline.
Is pluie masculine or feminine?
lapluie
The rule behind it
95.7% of -ie nouns are feminine
In context
J'ai envie de chanter sous la pluie.
I feel like singing in the rain.
Pendant combien de temps la pluie va-t-elle tomber ?
How long will this rain go on?
Ne laissez pas la bicyclette sous la pluie.
Don't leave the bicycle out in the rain.