Itoshima's climate is characterized by mild winters, with temperatures rarely dropping below freezing and averaging around 6-9°C in January and February. Spring brings a gradual warming trend, with March and April temperatures rising to an average of 13-16°C, while May sees a further increase to 20°C. Summer months are warm to hot, with July and August temperatures often reaching highs above 30°C, but also experiencing occasional heatwaves. Autumn is mild, with September still averaging around 25°C, before cooling down in October and November. Winters are generally cool, with December temperatures averaging around 8°C, and occasionally dipping below freezing.