Winters in Izumisano are mild, with temperatures rarely dropping below freezing and averaging around 6-9°C. Spring brings rapid warming, with temperatures increasing by up to 10°C between March and April. Summers are hot and humid, with temperatures often reaching above 30°C from June to August. Autumn is characterized by a gradual cooling, with temperatures decreasing steadily until winter sets in. Overall, the city experiences a moderate climate with minimal extreme temperature fluctuations throughout the year.