Harderwijk experiences a mild climate with distinct seasonal variations. Winters are chilly, with temperatures often below freezing, especially in January and February, but can occasionally rise above average. Spring brings gradual warming, with March and April temperatures rising steadily to around 6°C on average. Summers are warm, with July being the hottest month, averaging 18°C, while September marks a slight cooling trend. Autumn is similarly mild, with October and November temperatures dropping back down towards winter levels, but rarely below freezing.