Winters in Koga, Japan are cool and variable, with temperatures often dropping below freezing but also experiencing mild days. Spring arrives in late March, bringing warmer temperatures that steadily rise into the mid-20s by April and May. Summers are hot and humid, with July being the warmest month, while August is almost as warm. Autumn sees a return to milder weather, with September being one of the warmer months, but October cools down significantly. By November, temperatures drop back to cooler levels, similar to those experienced in winter.