C’est and il fait are not used in the same way. Il fait is used to talk about the weather. C’est is used to describe a thing or a situation.
Il fait + adjective (weather)
Il fait is used to talk about the weather.
- Il fait froid. (It is cold.)
- Il fait chaud. (It is hot.)
- Il fait beau. (The weather is nice.)
- Il fait mauvais. (The weather is bad.)
C’est + adjective (a thing)
C’est is used to talk about a thing, an object, or a situation.
- La neige ? C’est froid. (Snow? It is cold.)
- Le feu ? C’est chaud. (Fire? It is hot.)
- Versailles ? C’est beau. (Versailles? It is beautiful.)
- Ma recette de tarte à la vanille ? C’est mauvais. (My vanilla tart recipe? It is bad.)
Tip
Remember: il fait = weather; c’est = a thing.