Ciao Olivia,
it' just a homophone. We have two meanings for this word: "face" and "is" (verb)
In this second case "faccia" is the verb "fare" (to make) used in sentences about hope, possibility in the future, fear... something not real.
Normally this should be the end of the following: "Spero che non faccia troppo caldo"
"I hope it won't be too hot"
It is a very hard grammar structure for a beginner so I suggest you to pass it and came back later.
But what you can study now if you don't know is that we use the verb "fare" for the weather.
"essere" is used as well, but less, for exemple : "Il tempo è bello" = "Fa bel tempo".
I hope the answer will help you!