Il neige !
Eel nezh
It snows!
Simple
Il neige dehors, tout est recouvert de blanc.
Eel nezh duh-OR, too teh ruh-koo-VAIR duh BLAHN
It snows outside, everything is covered in white.
Natural descriptive
Il neige à gros flocons, c'est féerique mais attention au verglas !
Eel nezh ah groh flo-KON, seh fay-REEK meh ah-tahn-SYON oh vehr-GLAH
It's snowing in big flakes, it's magical but watch out for ice!
féerique = fairy-like/magical; verglas = black ice - the French are practical even when poetic
More French Weather Phrases