I would start searching in late Feb early March regardless of water temps. You can wait for the temps to be "right" but usually by then the bigger (trophy) bass have already beat you to the punch.
Also keep in mind that the whole lake won't go at the same time. I tend to start seriously looking once the water stays in the mid-upper fifties at sunrise. That and the next coming full moon's after. The temps at sunrise is a key component in my search. Don't let it being warm at sunset fool you into thinking they are ready still more night than day to cool this time of year until around mid-March.