Södermanland County C = Uppsala County S = Värmland County AC = Västerbotten County Y = Västernorrland County U = Västmanland County O = Västra Götaland County T = Örebro County E = Östergötland County The letters shown were on the vehicle registration plates until 1973. Municipalities Each county is further divided into municipalities or kommuner, ranging from only one (in Gotland County) to forty-nine (in Västra Götaland County). The total number of municipalities is 290. The northern municipalities are often large in size, but have small populations – the largest municipality is Kiruna with an area as large as the three southern provinces in Sweden (Scania, Blekinge and Halland) combined, but it only has a population of 25,000, and its density is about 1 / km2. Population Sweden has a population of 10 million as of January 2017. The mountainous north is considerably less populated than the southern and central regions, partly because the summer period lasts longer in the south, and this is where the more successful agricultural industries were originally established. Another historical reason is said to be the desired proximity to key trade routes and partners in continental Europe, e.g. Germany. As a result, all seven urban areas in Sweden with a population of 100,000 or more, are located in the southern half of the country. Cities Cities and towns in Sweden are neither political nor administrative entities; rather they are localities or urban areas, independent of municipal subdivisions. The largest city, in terms of population, is the capital Stockholm, in the east, the dominant city for culture and media, with a population of 1,250,000. The second largest city is Gothenburg, with 510,500, in the west. The third largest is Malmö in the south, with 258,000. The largest city in the north is Umeå with 76,000 inhabitants. Natural resources Sweden's natural resources include copper, gold, hydropower, iron ore, lead, silver, timber, uranium, and zinc. Environment Acid rain has become an issue because it is damaging soils and lakes and polluting the North Sea and the Baltic Sea. The HBV hydrology transport model has been used to analyze nutrient discharge to the Baltic from tributary watersheds. Climate Most of Sweden has a temperate climate, despite its northern latitude, with largely four distinct seasons and mild temperatures throughout the year. The winter in the far south is usually weak and is manifested only through some shorter periods with