Helsinki's winters are bitterly cold, with temperatures often dropping below -20°C in January and February, but occasionally rising above freezing. As the months progress, the mercury rises steadily, reaching a mild average of around 10°C in May and June, making it one of the warmest times of the year. Summer days are pleasant, with July being the warmest month on average, while August can feel cooler by comparison. Autumn brings temperatures back down to more seasonal levels, ranging from around -2°C to 15°C, before winter's chill returns in November and December. The temperature fluctuations throughout the year make Helsinki's climate quite changeable.