Grimsby's winters are typically cool and variable, with temperatures often below freezing in January and February, but occasionally rising above 18°C. As spring arrives in March, temperatures slowly warm up, reaching an average high of 23°C by the end of the month. Summer months see more consistent warmth, with July and August averaging around 18-20°C, while September and October experience a gradual cooling trend. Autumn can be quite changeable, with temperatures sometimes dropping below zero in November and December, but also occasionally rising above 16°C during these months. Overall, Grimsby's climate is generally mild, but subject to significant temperature fluctuations throughout the year.