Molarity is temperature dependent parameter. Volume of solution increase with increase in temperature diye to increase in intermolecular spaces and vice versa. Hence molarity is affected by temperature change.
Molarity (M) is defined as the number of moles of solute (n) divided by the volume (V) of the solution in liters.
It depends on the current humidity.
Water vapor certainly does evaporate from ice, as you can see in a vapor pressure chart. If the humidity is 100%, and the air temperature is the same as that of the ice, then the evaporation and condensation are in equilibrium; i.e. water evaporates as fast as it condenses, so there is no net change in humidity.