Due to the increased maritime moderation in the peninsular south, summer differences between the coastlines of the southernmost and northernmost regions are about  in summer and  in winter. This grows further when comparing areas in the northern interior where the winter difference in the far north is about  throughout the country. The warmest summers usually happen in the Mälaren Valley around Stockholm due to the vast landmass shielding the middle east coast from Atlantic low-pressure systems in July compared to the south and west. Daytime highs in Sweden's municipal seats vary from  to  in July and  to  in January. The colder temperatures are influenced by the higher elevation in the northern interior. At sea level instead, the coldest average highs range from  to . As a result of the mild summers, the arctic region of Norrbotten has some of the northernmost agriculture in the world.