Due to the joint action of the polar cold air front and the sea cold current, the temperature in central and southern Brazil fell to the lowest level in August for many years since 21 local time, resulting in large-scale precipitation and frost and other weather phenomena. As of the morning of the 22nd, the average rainfall in Rio city in 24 hours exceeded 125mm, and the area with the most precipitation nearly 150mm. A huge wave of three meters high was set off along the southern coast of Rio. Brazil’s Navy issued a 36 hour blockade of the southeastern coast from 9:00 on the 21st, banning any ship from going to sea. The northward movement of the Antarctic cold air and the passage of the sea cold current at the same time led to the significant cooling and precipitation in central and southern Brazil. According to the meteorological department forecast, the temperature in Sao Paulo will be maintained at 8 to 13 degrees centigrade this weekend. Sao Paulo, the capital of the state, also had a rare low temperature of 8.2 degrees Celsius in 60 years in the early morning of the 22nd. According to weather forecast, the lowest temperature in Sao Paulo may drop to 7 degrees centigrade on the 23rd. < p > < p > in addition, starting from the 21st, dozens of cities in the southern Brazilian states of Nandahe and Santa Catarina experienced a rare low temperature below zero ℃ in August. With the low temperature, there was a wide range of snow and frost. Except for Brazil, due to the cold air and cold current, the temperature in Argentina, Chile, Uruguay, Paraguay, Bolivia and Peru in South America has dropped significantly.