Niiza, Japan's climate is marked by significant seasonal variation. Winters are chilly and unpredictable, with temperatures fluctuating between -7°C and 18°C, averaging around 4-7°C in January and December. Spring brings gentle warming, with temperatures rising to averages of 12-14°C in March and April, while summer months of June to August are warm to hot, peaking at averages above 25°C. Autumn is mild, with temperatures ranging from 5-22°C in October and November.