Otsu experiences a gradual warming trend throughout the year. Winter is cool, with temperatures ranging from -4°C in January to -3°C in February, but mild compared to other parts of Japan, with average highs around 5-7°C. As spring approaches, temperatures rise rapidly, reaching averages above 14°C by April and continuing to climb into May, which sees highs of up to 30°C. Summer is hot and humid, with temperatures frequently exceeding 33°C in June and July, and August's heat index often reaches similar levels. Autumn brings a welcome cooling trend, with temperatures dropping back down to around 5-7°C by October and November, before the cycle begins again in December.