Climate: Uruguay has a mild climate. In January and February, during the summer time temperature hits an average of 21,7°C, and in June, during the winter time, it decreases to 10°C. Uruguay has an average annual rainfall of approximately 1000 mm. During the months of winter, a strong wind called "pampero", sometimes blows from the Southeast cooling up the atmosphere. Frosts are hardly seen in most areas of the country. Natural Resources: Agriculture is Uruguay´s main resource and minerals are becoming scarce. Generally, its soil is very fertile except the marshy regions. Hydroelectric energy is a vital aspect of the country. The following are important dams in the country: the Salto Grande hydroelectric power station on the Uruguay river which the country shares with Argentina, and the Rincón del Bonete power station on the Río Negro, the dam that best uses hydroenergy in the country. The electric system has been nationalized. Agriculture and Livestock Breeding: Uruguay´s economy is based on livestock breeding, a main activity in the country that represents more than 40% of its annual exports as meat, wool, skin and hides. A moderate climate together with slight temperature changes and rains evenly distributed enable cattle raising all year round. In 1998, Uruguay had 13 million heads of sheep, 10.9 million of cattle, 500,000 of horses and 270.000 heads of pigs. Although 7% of its territory is used for cultivation, the surface intended for agriculture is gradually increasing. Its main agricultural products include the following: rice (865,000 tons), wheat (500,000 tons), corn (225,600 tons), sugar cane (160,000 tons) , potato (papa, 150,000 tons), sorghum (97,400 tons) oats, and sugar beet. Artigas Canelones Cerro largo Colonia Durazno Flores Florida Lavalleja Maldonado Montevideo Paysandú Río Negro Rivera Rocha Salto San José Soriano Tacuarembo Treinta y Tres