The weather ratio in September in Tokyo (Japan) comprises 8% clear and sunny days, 4% partly cloudy days, 24% cloudy days, and 64% rainy days. September in Tokyo sees an extremely large amount of rain, and an umbrella is indispensable. The average temperature in Tokyo in September is 25°C. The highest temperature is 25°C, the lowest temperature is 21°C, and the temperature doesn't change much. Roughly half of the days of the month are cloudy, so sunlight his highly valued, It is, on average, a windy place.