ya'll should note wind chill is a measure of how cold it feels to a warm human body, not a solid piece of rock or ice already at ambient environmental temperature (a.e.t.). The wind chill factor essentially describes how the skin is cooled more quickly with a wind than without (duh!). So something that's already at the a.e.t. will experience no cooling effect from the wind. In fact, something below a.e.t. will experince a wind warming effect! Surface moisture also plays a role, but not nearly as much as....
also, i'd agree that it best to be adventuresome and go back home only when you see it's shitty out from personal observations.