Oyama, Japan experiences a temperate climate with distinct seasonal changes. Winters are chilly and occasionally frosty, with temperatures often below freezing in January and December, but also experiencing milder days around 18-22°C. As spring arrives in March and April, temperatures rise rapidly, frequently reaching highs above 20°C by late April. Summers are warm to hot, with July and August being the hottest months, while September brings a welcome cooldown. Autumn is mild, with October and November enjoying temperatures ranging from 4-22°C.