Kawaguchi's weather is marked by a distinct seasonal pattern. Winters are cold and variable, with temperatures often dropping below freezing but also experiencing mild days in the mid-teens Celsius. As spring arrives, temperatures gradually warm up, reaching averages of around 14°C in April and May. Summer is hot and humid, with temperatures frequently soaring above 30°C from June to August. Autumn brings a welcome respite, with comfortable temperatures returning in September and October, before cooling down again in November and December.