Winters in Toyokawa are cool, with temperatures ranging from around -3°C to 17°C, averaging 6-8°C. Spring brings gradual warming, with March and April temperatures rising to an average of 12°C and 15°C respectively. Summer is hot and humid, with July and August often reaching highs above 35°C, while September cools slightly, still averaging around 24°C. Autumn temperatures are mild, similar to spring, before cooling again in winter.