Dews getting to about 62 will kick up the frizz for me, but I can get frizz pretty easily anyway due to wind here. Two things help me: one, using a lot of gel and a hard hold one; two, pixiecurl diffusing. I use KCCC + BRHG and quite a bit of it--enough to get a lot of crunch by the time it dries. Once I SOTC, I've never had an issue with the curls being too stiff or unnatural looking. I actually get compliments when it's still crunchy, which I think is a little odd because IMO it looks like poop, but OK. I also pixiecurl at least until I've got a good cast on, so 50-75% dry. If I do these two things, I'm pretty much frizz-free on day one and can keep frizz to a minimum on day two.
Former longhair, now CG, living in N. California where the fog meets the wind
3a/b, fine, normal porosity/elasticity, high density
Conditioner wash and style, sometimes with a dab of BRHG.