There are a couple of sure signs that Winter is on the wane. The loudest is the emergence of Spring peepers. Their chorus is a sign that they (and the mud they have hibernating within) have warmed. These amphibians are ready for action. The plaintive cries of males looking for a mate drown out any other noises. These randy frogs are relentless with their come-hither din.
A more subtle sign is the greening of weeping willows. A light green umbrella of colorful branches stands out among the gray bark and leaves that still hang on to a few trees. Between the peepers and willows, I know that Spring is here.