Hiroshima's winters are cool and unpredictable, with temperatures fluctuating between freezing lows and mild highs. Spring brings gradual warming, with temperatures rising steadily through March and April. Summers are hot and humid, with July and August often reaching sweltering highs. Autumn is a brief respite from the heat, with temperatures cooling down by September, but still warm until November. Winters return in December, with temperatures dropping again to chilly lows.