Yamaguchi's climate is characterized by mild winters with occasional cold snaps, as seen in the January and December averages of around 5°C and 8°C respectively. Spring brings a steady warming trend, reaching average highs of 15°C in April and 19°C in May. Summer months are hot and humid, with temperatures often soaring above 30°C from June to August. Autumn is mild, with September's average high temperature of 24°C, before cooling down to around 12°C by November. The overall temperature range remains relatively consistent throughout the year, with minimal seasonal extremes.