Climate: The climate in Sweden is a cold climate, characterized by dark and long winters with minimum temperatures of -15°C/-20°C; in the north the ice persist from October to May and winter obstruct navigation in the Gulf of Bothnia. Summer is short, but with long days of light (in summer in most areas in the north of the country the sun never sets ever), with temperatures ranging between 15°C and 20°C. In central and southern Sweden the winters are short and quite cold, and summer temperatures are mild, with a many hours of sunshine and daylight. In the northeast meanwhile the winters are severe, the more so as you travel further north, while the summers can be surprisingly warm. In the far north the winters are also severe, with snow lying the year-round on elevated areas, and the summers are short and changeable. The rainfall is concentrated mainly in summer and autumn, the average is 800 to 1000 mm annually. The considerable length from north to south of the country involve in significant climatic differences between the extreme north and the extreme south. The average temperatures in Stockholm are -1°C in January, 12°C in May, 19°C in July, while in Kiruna, in the far north of the country, the average temperature is -8°C in January, 7°C in May and 15°C in July.