Bilecik experiences a moderate climate with significant seasonal changes. Winters are cold and snowy, with temperatures often below freezing in January and February. As spring approaches, temperatures rise gradually, reaching pleasant highs in April and May. Summers are warm to hot, with July and August being the hottest months, while autumns see a cooling trend, with mild temperatures prevailing from September to November. Frosts return in winter, bringing temperatures back down to near-freezing levels by December.