"It is raining and it is foggy."
Translation:Il pleut et il y a du brouillard.
"Il fait" is used with adjectives: beau, mauvais, chaud, froid, frais. "Il y a" is used with nouns, e.g., du vent, du brouillard, du soleil, etc.
And descriptive verbs with actual on-going weather processes, correct? For example: Il pleut, il neige: "It's raining, it's snowing".
There still seems to be some idiomatic preferences,, depending on the phenomenon. For instance, my inclination as a native English-speaker would be to say,il est venteux rather than il fait du vent because "it's windy" is definitely the much-preferred English way of remarking on the weather phenomenon, but idiom is idiom, and can't really be argued with.
You would not say "il est venteux", but "il vente" or "le temps est venteux".
This is inconsistent, because in this sentence structure, you wouldn't say "il y a du vente", would you?
"Il pleut et il y a du brouillard" Why can't I use an "il fait" or "il y a" construction for the first part of the sentence?
"Il fait" is followed by an adjective: il fait beau, mauvais, froid, chaud...
"Il y a" is followed by a noun: il y a du vent, des nuages
"Il pleut", "il neige", "il gèle"... are verbs you have to use with the impersonal pronoun "il", like "it is raining, it is snowing, it is freezing".