Kokubunji's winters are chilly, with temperatures often below freezing and average lows around 4°C in January. As spring approaches, temperatures gradually warm up, reaching averages of 14°C by April. Summer months bring hot days, with July and August experiencing highs above 35°C, while autumn sees a return to milder conditions, with October's temperatures averaging around 17°C. The temperature fluctuations are significant, with monthly averages varying between 4°C in January and 27°C in August. By November, temperatures begin to drop again, returning to the chilly averages seen in winter.