"The weather is cool."
Translation:Il fait frais.
“frais” is cool, not cold. It’s less cold than cold. Also in young popular language we also use “frais” to mean the same thing as “cool” in english (same thing as “figo” in italian or “mojosa” in esperanto), though “cool” stays more used in common language (so “frais” ends being a little more unusual, weird, and with a slightly stronger meaning I find).
Like said aside, it also means more of “fresh”, in the meaning of new, the opposed of outdated/perished/decomposing. You say “poisson frais” if it was fished recently, and “du pain frais” to mean bread that’s still hot (after cooking), which is kinda contradictory and weird but really common.