Koganei experiences a temperate climate with distinct seasonal changes. Winters are cold and chilly, with temperatures often below freezing in January and December, but occasionally rising above 18°C/22°C in February. Spring is mild and pleasant, with temperatures gradually warming up from March to May, reaching an average high of around 30°C in May. Summers are warm and humid, with temperatures frequently hitting the mid-30s in July and August. Autumn brings a return to cooler temperatures, with September and October averages dipping back down into the teens, before winter's chill sets in once again.