The coastal plain as far south as Santos is a region of high temperatures and great humidity. The year is usually divided into a winter (_inverno_) and summer (_verão_), corresponding approximately to a dry and wet season. The "dry" season, however, is a season of moderate rainfall, except on the north-east coast where arid conditions prevail. Another exception is that of the Pernambuco coast, where the rainy season comes between March and August, with the heaviest rainfall from May to July, which is the time of the southern winter. Going southward there is also a gradual decrease in the mean annual temperature, the difference between Rio de Janeiro and the Amazon being about 5°. The north-east coast, which is sandy and barren, shows an average mean annual temperature (at Fortaleza) of nearly 80° F., which is slightly higher than those of Maranhão and Pará. At Pernambuco the mean summer temperature is 79.5° and that of winter 76.8°, which are about 3° lower than the mean temperature of Bahia in summer, and 5° higher than the Bahia mean in winter. South of Bahia there is a gradual increase in the rainfall, that of Rio de Janeiro exceeding 43 in. per annum. At Santos the rainfall is exceptionally heavy and the mean temperature high, but below that point the climatic conditions are considerably modified, the range in temperature being greater, the mean annual temperature lower, and the rainfall more evenly distributed throughout the year. The winds are more variable, and the seasons are more sharply defined. In Rio Grande do Sul the range in temperature is from 26° to 80°, the climate being similar to that of Uruguay. At Pelotas, a sea-level port on Lagôa dos Patos, the mean annual temperature is about 63° and the annual rainfall about 42 in. Extreme variations in temperature are often produced by cold south-west storms from the Argentine pampas, which sweep across southern Brazil as far north as Cape Frio, the fall in temperature sometimes being 22° to 27°. These storms usually last from two to three days and cause much discomfort. Winter rains are more frequent in southern Brazil, and violent storms prevail in August and September. At Blumenau, on the Santa Catharina coast, the annual rainfall is 53 in.