From the subtropical climate to the cultural habits, Porto Alegre is fairly different from the other state capitals in Brazil. Founded in 1742 by immigrants from the Portuguese archipelago of Azores, the capital of Rio Grande do Sul was the destination of thousands of immigrants from Portugal and Italy - like many other cities in Brazil but also from other European countries, particularly Germany and Poland.
Besides that, as the state is located far down the south of Brazil, the gauchos, as people from Rio Grande do Sul are called, share several cultural traits with their neighbours from Argentina and Uruguay, from the folklore music to the habit of drinking the mate infusion, or chimarrao.
Porto Alegre lies on the eastern bank of the Guaíba River, right at the convergence point of five other rivers, which together form the enormous Lagoa dos Patos (Ducks Lagoon). Its 497 square kilometres are covered with more than one million trees, making it one of the greenest cities in Brazil, despite being the nucleus of the fourth-most populous metropolitan area in the country, with roughly four million inhabitants. There are over 1.4 million people living within the boundaries of Porto Alegre.

Temperatures are a lot milder in Porto Alegre than they are in most of the Brazilian capitals, with an annual temperature average of 19.5ºC and cold winters that have historical records of snow and subzero temperatures. The four seasons are very defined, though, and during the summer, temperatures may go well beyond 35ºC. The capital of Rio Grande do Sul is also famous for featuring one of the highest human development index figures in the whole country.

SOURCE: http://www.fifa.com/worldcup/
TOURISM IN PORTO ALEGRE
WHAT TO DO IN PORTO ALEGRE
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Sediments color Lagoa dos Patos (English: Duck Lagoon), tan and frame the nearby Brazilian coastline. Lagoa dos Patos is the second largest lagoon in Latin America and the biggest in Brazil. It is located in the state of Rio Grande do Sul, southern Brazil. The lagoon is 174 miles (280 km) long, has a maximum width of 44 miles (70 km), and a total area of 3,803 sq. mi. (9,850 km). It is separated from the Atlantic Ocean by a sandbar about 5 miles (8 kilometers) wide. The Rio Grande, at the south end of Lagoa dos Patos, forms the outlet to the Atlantic.
According to the Ramsar Convention for the conservation and sustainable utilization of wetlands, recognizing the fundamental ecological functions of wetlands and their economic, cultural, scientific, and recreational value is internationally important.
Lagoa do Peixe National Park is 34,4000 hectares and is made up of the Campos Sulinos (Southern Fields) and Mata Atlântica (Atlantic Rain Forest) biomes. It includes representative samples of the ecosystems of the Rio Grande do Sul coastal zone such as saltmarsh, coastal dunes and lagoons, arboreal habitat, restingas, beach and a marine area. The beauty of the park's dunes and lagoons can be appreciated by all park visitors. Lagoa do Peixe National Park was named after the lagoon found within the reserve with the same name. Lagoa do Peixe is the largest lagoon within the park; it is shallow and is about 35 km long, making it an important feeding ground for birds.