That's like asking," What makes a woman a hottie ?" There are so many variables that there isn't a cut and dried answer. For instance; is there any remaining ice, will there be snow, is it windy, is the water in question at elevation? A ballpark guess would be a week and a half if the temps were actually around 20 and assuming a daytime high in the thirties. That's without excessive wind or snow. Could be a little sooner if the conditions were perfect, but that isn't the norm. Lakes that still have cover could tighten up a lot faster, but there will be thin spots to watch out for. Everyone should exercise caution, and watch out for your fellow anglers.
