it is important to note that Freezing level is the altitude at which the 0°C isotherm is reached. But this is in a free atmosphere not near to the ground. So in mountain if the Freezing level is at 1500m it is not sure that the local temperature at 2m above ground level is the same. It is mainly an indication of temperature of the air mass. But it is useful to know it as it shows when locally the rain turns to snowfall
It is interesting to look at Airgram as it gives an idea of the 0°C isotherm in the next days at a location.