You might spend a lot of your holiday inside, but if you want to see more of the area, taking a look at local weather data can help you. The hottest months are usually August and July, with an average temperature of 25°C, while the coldest months are January and February, with an average of 6°C. The rainiest months in Kokubunji are September, October, June and July, with each month seeing an average of 234 mm of rainfall.