Winters in Cergy are cold and unpredictable, with temperatures often dropping below freezing and averaging around 4-6°C. Spring brings a gradual warming trend, with March marking the beginning of a steady increase in temperatures, reaching an average high of 25°C by April. Summer is mild and warm, with July being the warmest month, but even then temperatures rarely exceed 30°C. Autumn is generally cool, with temperatures dropping back down to around 0-10°C as winter approaches again. The temperature fluctuations throughout the year are quite significant, with some months experiencing nearly a 40°C difference between their highest and lowest recorded temperatures.