Bristol's winters are cool and unpredictable, with temperatures often dropping below freezing and averaging around 0°C in January. Spring brings gradual warming, with March averaging 6°C and April a mild 11°C, but still prone to cold snaps. Summer is warm, but not hot, with July and August temperatures rarely exceeding 34°C on average. Autumn sees a return to cooler temperatures, with September averaging 19°C before dropping to around 15°C in October. Winters are generally the coldest period, with December's average temperature only slightly higher than January's.