Tosu's weather is characterized by a gradual warming trend throughout the year. Winters, spanning January and February, are cool with temperatures averaging around 6-9°C, while springs are mild, with March and April temperatures rising to averages of 13-16°C. Summers are hot and humid, with June to August temperatures often reaching highs above 30°C, peaking in July at an average of 28°C. Autumn brings a welcome respite from the heat, with September's warm days gradually giving way to cooler temperatures by October, before winter's chill returns.